Does anyone know how to add 2 binary numbers, entered as binary, in Java?
For example, 1010 + 10 = 1100.
Use Integer.parseInt(String, int radix).
public static String addBinary(){
// The two input Strings, containing the binary representation of the two values:
String input0 = "1010";
String input1 = "10";
// Use as radix 2 because it's binary
int number0 = Integer.parseInt(input0, 2);
int number1 = Integer.parseInt(input1, 2);
int sum = number0 + number1;
return Integer.toBinaryString(sum); //returns the answer as a binary value;
}
To dive into fundamentals:
public static String binaryAddition(String s1, String s2) {
if (s1 == null || s2 == null) return "";
int first = s1.length() - 1;
int second = s2.length() - 1;
StringBuilder sb = new StringBuilder();
int carry = 0;
while (first >= 0 || second >= 0) {
int sum = carry;
if (first >= 0) {
sum += s1.charAt(first) - '0';
first--;
}
if (second >= 0) {
sum += s2.charAt(second) - '0';
second--;
}
carry = sum >> 1;
sum = sum & 1;
sb.append(sum == 0 ? '0' : '1');
}
if (carry > 0)
sb.append('1');
sb.reverse();
return String.valueOf(sb);
}
Martijn is absolutely correct, to piggyback and complete the answer
Integer.toBinaryString(sum);
would give your output in binary as per the OP question.
You can just put 0b in front of the binary number to specify that it is binary.
For this example, you can simply do:
Integer.toString(0b1010 + 0b10, 2);
This will add the two in binary, and Integer.toString() with 2 as the second parameter converts it back to binary.
The original solution by Martijn will not work for large binary numbers. The below code can be used to overcome that.
public String addBinary(String s1, String s2) {
StringBuilder sb = new StringBuilder();
int i = s1.length() - 1, j = s2.length() -1, carry = 0;
while (i >= 0 || j >= 0) {
int sum = carry;
if (j >= 0) sum += s2.charAt(j--) - '0';
if (i >= 0) sum += s1.charAt(i--) - '0';
sb.append(sum % 2);
carry = sum / 2;
}
if (carry != 0) sb.append(carry);
return sb.reverse().toString();
}
public class BinaryArithmetic {
/*-------------------------- add ------------------------------------------------------------*/
static String add(double a, double b) {
System.out.println(a + "first val :" + b);
int a1 = (int) a;
int b1 = (int) b;
String s1 = Integer.toString(a1);
String s2 = Integer.toString(b1);
int number0 = Integer.parseInt(s1, 2);
int number1 = Integer.parseInt(s2, 2);
int sum = number0 + number1;
String s3 = Integer.toBinaryString(sum);
return s3;
}
/*-------------------------------multiply-------------------------------------------------------*/
static String multiply(double a, double b) {
System.out.println(a + "first val :" + b);
int a1 = (int) a;
int b1 = (int) b;
String s1 = Integer.toString(a1);
String s2 = Integer.toString(b1);
int number0 = Integer.parseInt(s1, 2);
int number1 = Integer.parseInt(s2, 2);
int sum = number0 * number1;
String s3 = Integer.toBinaryString(sum);
return s3;
}
/*----------------------------------------substraction----------------------------------------------*/
static String sub(double a, double b) {
System.out.println(a + "first val :" + b);
int a1 = (int) a;
int b1 = (int) b;
String s1 = Integer.toString(a1);
String s2 = Integer.toString(b1);
int number0 = Integer.parseInt(s1, 2);
int number1 = Integer.parseInt(s2, 2);
int sum = number0 - number1;
String s3 = Integer.toBinaryString(sum);
return s3;
}
/*--------------------------------------division------------------------------------------------*/
static String div(double a, double b) {
System.out.println(a + "first val :" + b);
int a1 = (int) a;
int b1 = (int) b;
String s1 = Integer.toString(a1);
String s2 = Integer.toString(b1);
int number0 = Integer.parseInt(s1, 2);
int number1 = Integer.parseInt(s2, 2);
int sum = number0 / number1;
String s3 = Integer.toBinaryString(sum);
return s3;
}
}
Another interesting but long approach is to convert each of the two numbers to decimal, adding the decimal numbers and converting the answer obtained back to binary!
Java solution
static String addBinary(String a, String b) {
int lenA = a.length();
int lenB = b.length();
int i = 0;
StringBuilder sb = new StringBuilder();
int rem = Math.abs(lenA-lenB);
while(rem >0){
sb.append('0');
rem--;
}
if(lenA > lenB){
sb.append(b);
b = sb.toString();
}else{
sb.append(a);
a = sb.toString();
}
sb = new StringBuilder();
char carry = '0';
i = a.length();
while(i > 0){
if(a.charAt(i-1) == b.charAt(i-1)){
sb.append(carry);
if(a.charAt(i-1) == '1'){
carry = '1';
}else{
carry = '0';
}
}else{
if(carry == '1'){
sb.append('0');
carry = '1';
}else{
carry = '0';
sb.append('1');
}
}
i--;
}
if(carry == '1'){
sb.append(carry);
}
sb.reverse();
return sb.toString();
}
public String addBinary(String a, String b) {
int carry = 0;
StringBuilder sb = new StringBuilder();
for(int i = a.length() - 1, j = b.length() - 1;i >= 0 || j >= 0;i--,j--){
int sum = carry + (i >= 0 ? a.charAt(i) - '0':0) + (j >= 0 ? b.charAt(j) - '0' : 0);
sb.append(sum%2);
carry =sum / 2;
}
if(carry > 0) sb.append(carry);
sb.reverse();
return sb.toString();
}
I've actually managed to find a solution to this question without using the stringbuilder() function. Check this out:
public void BinaryAddition(String s1,String s2)
{
int l1=s1.length();int c1=l1;
int l2=s2.length();int c2=l2;
int max=(int)Math.max(l1,l2);
int arr1[]=new int[max];
int arr2[]=new int[max];
int sum[]=new int[max+1];
for(int i=(arr1.length-1);i>=(max-l1);i--)
{
arr1[i]=(int)(s1.charAt(c1-1)-48);
c1--;
}
for(int i=(arr2.length-1);i>=(max-l2);i--)
{
arr2[i]=(int)(s2.charAt(c2-1)-48);
c2--;
}
for(int i=(sum.length-1);i>=1;i--)
{
sum[i]+=arr1[i-1]+arr2[i-1];
if(sum[i]==2)
{
sum[i]=0;
sum[i-1]=1;
}
else if(sum[i]==3)
{
sum[i]=1;
sum[i-1]=1;
}
}
int c=0;
for(int i=0;i<sum.length;i++)
{
System.out.print(sum[i]);
}
}
The idea is same as discussed in few of the answers, but this one is a much shorter and easier to understand solution (steps are commented).
// Handles numbers which are way bigger.
public String addBinary(String a, String b) {
StringBuilder sb = new StringBuilder();
int i = a.length() - 1;
int j = b.length() -1;
int carry = 0;
while (i >= 0 || j >= 0) {
int sum = carry;
if (j >= 0) { sum += b.charAt(j--) - '0' };
if (i >= 0) { sum += a.charAt(i--) - '0' };
// Added number can be only 0 or 1
sb.append(sum % 2);
// Get the carry.
carry = sum / 2;
}
if (carry != 0) { sb.append(carry); }
// First reverse and then return.
return sb.reverse().toString();
}
i tried to make it simple this was sth i had to deal with with my cryptography prj its not efficient but i hope it
public String binarysum(String a, String b){
int carry=0;
int maxim;
int minim;
maxim=Math.max(a.length(),b.length());
minim=Math.min(a.length(),b.length());
char smin[]=new char[minim];
char smax[]=new char[maxim];
if(a.length()==minim){
for(int i=0;i<smin.length;i++){
smin[i]=a.charAt(i);
}
for(int i=0;i<smax.length;i++){
smax[i]=b.charAt(i);
}
}
else{
for(int i=0;i<smin.length;i++){
smin[i]=b.charAt(i);
}
for(int i=0;i<smax.length;i++){
smax[i]=a.charAt(i);
}
}
char[]sum=new char[maxim];
char[] st=new char[maxim];
for(int i=0;i<st.length;i++){
st[i]='0';
}
int k=st.length-1;
for(int i=smin.length-1;i>-1;i--){
st[k]=smin[i];
k--;
}
// *************************** sum begins here
for(int i=maxim-1;i>-1;i--){
char x= smax[i];
char y= st[i];
if(x==y && x=='0'){
if(carry==0)
sum[i]='0';
else if(carry==1){
sum[i]='1';
carry=0;
}
}
else if(x==y && x=='1'){
if(carry==0){
sum[i]='0';
carry=1;
}
else if(carry==1){
sum[i]='1';
carry=1;
}
}
else if(x!=y){
if(carry==0){
sum[i]='1';
}
else if(carry==1){
sum[i]='0';
carry=1;
}
} }
String s=new String(sum);
return s;
}
class Sum{
public int number;
public int carry;
Sum(int number, int carry){
this.number = number;
this.carry = carry;
}
}
public String addBinary(String a, String b) {
int lengthOfA = a.length();
int lengthOfB = b.length();
if(lengthOfA > lengthOfB){
for(int i=0; i<(lengthOfA - lengthOfB); i++){
b="0"+b;
}
}
else{
for(int i=0; i<(lengthOfB - lengthOfA); i++){
a="0"+a;
}
}
String result = "";
Sum s = new Sum(0,0);
for(int i=a.length()-1; i>=0; i--){
s = addNumber(Character.getNumericValue(a.charAt(i)), Character.getNumericValue(b.charAt(i)), s.carry);
result = result + Integer.toString(s.number);
}
if(s.carry == 1) { result += s.carry ;}
return new StringBuilder(result).reverse().toString();
}
Sum addNumber(int number1, int number2, int carry){
Sum sum = new Sum(0,0);
sum.number = number1 ^ number2 ^ carry;
sum.carry = (number1 & number2) | (number2 & carry) | (number1 & carry);
return sum;
}
import java.util.*;
public class BitAddition {
/**
* #param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner sc = new Scanner(System.in);
int len = sc.nextInt();
int[] arr1 = new int[len];
int[] arr2 = new int[len];
int[] sum = new int[len+1];
Arrays.fill(sum, 0);
for(int i=0;i<len;i++){
arr1[i] =sc.nextInt();
}
for(int i=0;i<len;i++){
arr2[i] =sc.nextInt();
}
for(int i=len-1;i>=0;i--){
if(sum[i+1] == 0){
if(arr1[i]!=arr2[i]){
sum[i+1] = 1;
}
else if(arr1[i] ==1 && arr2[i] == 1){
sum[i+1] =0 ;
sum[i] = 1;
}
}
else{
if((arr1[i]!=arr2[i])){
sum[i+1] = 0;
sum[i] = 1;
}
else if(arr1[i] == 1){
sum[i+1] = 1;
sum[i] = 1;
}
}
}
for(int i=0;i<=len;i++){
System.out.print(sum[i]);
}
}
}
One of the simple ways is as:
convert the two strings to char[] array and set carry=0.
set the smallest array length in for loop
start for loop from the last index and decrement it
check 4 conditions(0+0=0, 0+1=1, 1+0=1, 1+1=10(carry=1)) for binary addition for each element in both the arrays and reset the carry accordingly.
append the addition in stringbuffer
append rest of the elements from max size array to stringbuffer but check consider carry while appending
print stringbuffer in reverse order for the answer.
//The java code is as
static String binaryAdd(String a, String b){
int len = 0;
int size = 0;
char[] c1 = a.toCharArray();
char[] c2 = b.toCharArray();
char[] max;
if(c1.length > c2.length){
len = c2.length;
size = c1.length;
max = c1;
}
else
{
len = c1.length;
size = c2.length;
max = c2;
}
StringBuilder sb = new StringBuilder();
int carry = 0;
int p = c1.length - 1;
int q = c2.length - 1;
for(int i=len-1; i>=0; i--){
if(c1[p] == '0' && c2[q] == '0'){
if(carry == 0){
sb.append(0);
carry = 0;
}
else{
sb.append(1);
carry = 0;
}
}
if((c1[p] == '0' && c2[q] == '1') || (c1[p] == '1' && c2[q] == '0')){
if(carry == 0){
sb.append(1);
carry = 0;
}
else{
sb.append(0);
carry = 1;
}
}
if((c1[p] == '1' && c2[q] == '1')){
if(carry == 0){
sb.append(0);
carry = 1;
}
else{
sb.append(1);
carry = 1;
}
}
p--;
q--;
}
for(int j = size-len-1; j>=0; j--){
if(max[j] == '0'){
if(carry == 0){
sb.append(0);
carry = 0;
}
else{
sb.append(1);
carry = 0;
}
}
if(max[j] == '1'){
if(carry == 0){
sb.append(1);
carry = 0;
}
else{
sb.append(0);
carry = 1;
}
}
}
if(carry == 1)
sb.append(1);
return sb.reverse().toString();
}
import java.io.;
import java.util.;
public class adtbin {
static Scanner sc=new Scanner(System.in);
public void fun(int n1) {
int i=0;
int sum[]=new int[20];
while(n1>0) {
sum[i]=n1%2; n1=n1/2; i++;
}
for(int a=i-1;a>=0;a--) {
System.out.print(sum[a]);
}
}
public static void main() {
int m,n,add;
adtbin ob=new adtbin();
System.out.println("enter the value of m and n");
m=sc.nextInt();
n=sc.nextInt();
add=m+n;
ob.fun(add);
}
}
you can write your own One.
long a =100011111111L;
long b =1000001111L;
int carry = 0 ;
long result = 0;
long multiplicity = 1;
while(a!=0 || b!=0 || carry ==1){
if(a%10==1){
if(b%10==1){
result+= (carry*multiplicity);
carry = 1;
}else if(carry == 1){
carry = 1;
}else{
result += multiplicity;
}
}else if (b%10 == 1){
if(carry == 1){
carry = 1;
}else {
result += multiplicity;
}
}else {
result += (carry*multiplicity);
carry = 0;
}
a/=10;
b/=10;
multiplicity *= 10;
}
System.out.print(result);
it works just by numbers , no need string , no need SubString and ...
package Assignment19thDec;
import java.util.Scanner;
public class addTwoBinaryNumbers {
private static Scanner sc;
public static void main(String[] args) {
sc = new Scanner(System.in);
System.out.println("Enter 1st Binary Number");
int number1=sc.nextInt();
int reminder1=0;
int number2=sc.nextInt();
int reminder2=0;
int carry=0;
double sumResult=0 ;int add = 0
;
int n;
int power=0;
while (number1>0 || number2>0) {
/*System.out.println(number1 + " " +number2);*/
reminder1=number1%10;
number1=number1/10;
reminder2=number2%10;
number2=number2/10;
/*System.out.println(reminder1 +" "+ reminder2);*/
if(reminder1>1 || reminder2>1 ) {
System.out.println("not a binary number");
System.exit(0);
}
n=reminder1+reminder2+carry;
switch(n) {
case 0:
add=0; carry=0;
break;
case 1: add=1; carry=0;
break;
case 2: add=0; carry=1;
break;
case 3: add=1;carry=1;
break;
default: System.out.println("not a binary number ");
}
sumResult=add*(Math.pow(10, power))+sumResult;
power++;
}
sumResult=carry*(Math.pow(10, power))+sumResult;
System.out.println("\n"+(int)sumResult);
}
}
Try this, tested with binary and decimal and its self explanatory
public String add(String s1, String s2, int radix){
int s1Length = s1.length();
int s2Length = s2.length();
int reminder = 0;
int carry = 0;
StringBuilder result = new StringBuilder();
int i = s1Length -1;
int j = s2Length -1;
while (i >=0 && j>=0) {
int operand1 = Integer.valueOf(s1.charAt(i)+"");
int operand2 = Integer.valueOf(s2.charAt(j)+"");
reminder = (operand1+operand2+carry) % radix;
carry = (operand1+operand2+carry) / radix;
result.append(reminder);
i--;j--;
}
while(i>=0){
int operand1 = Integer.valueOf(s1.charAt(i)+"");
reminder = (operand1+carry) % radix;
carry = (operand1+carry) / radix;
result.append(reminder);
i--;
}
while(j>=0){
int operand1 = Integer.valueOf(s2.charAt(j)+"");
reminder = (operand1+carry) % radix;
carry = (operand1+carry) / radix;
result.append(reminder);
j--;
}
return result.reverse().toString();
}
}
static int addBinaryNumbers(String a, String b) {
int firstToDecimal = 0;
int secondToDecimal = 0;
for (int i = a.length() - 1, count = 0; i >= 0; i--, count++) {
firstToDecimal += (Math.pow(2, count) * Integer.parseInt(String.valueOf(a.toCharArray()[i])));
}
for (int i = b.length() - 1, count = 0; i >= 0; i--, count++) {
secondToDecimal += (Math.pow(2, count) * Integer.parseInt(String.valueOf(b.toCharArray()[i])));
}
return firstToDecimal + secondToDecimal;
}
public static void main(String[] args) {
System.out.println(addBinaryNumbers("101", "110"));
}
here's a python version that
def binAdd(s1, s2):
if not s1 or not s2:
return ''
maxlen = max(len(s1), len(s2))
s1 = s1.zfill(maxlen)
s2 = s2.zfill(maxlen)
result = ''
carry = 0
i = maxlen - 1
while(i >= 0):
s = int(s1[i]) + int(s2[i])
if s == 2: #1+1
if carry == 0:
carry = 1
result = "%s%s" % (result, '0')
else:
result = "%s%s" % (result, '1')
elif s == 1: # 1+0
if carry == 1:
result = "%s%s" % (result, '0')
else:
result = "%s%s" % (result, '1')
else: # 0+0
if carry == 1:
result = "%s%s" % (result, '1')
carry = 0
else:
result = "%s%s" % (result, '0')
i = i - 1;
if carry>0:
result = "%s%s" % (result, '1')
return result[::-1]
import java.util.Scanner;
{
public static void main(String[] args)
{
String b1,b2;
Scanner sc= new Scanner(System.in);
System.out.println("Enter 1st binary no. : ") ;
b1=sc.next();
System.out.println("Enter 2nd binary no. : ") ;
b2=sc.next();
int num1=Integer.parseInt(b1,2);
int num2=Integer.parseInt(b2,2);
int sum=num1+num2;
System.out.println("Additon is : "+Integer.toBinaryString(sum));
}
}
Related
I try for an exercice to add
String nb = "135";
String nb2 = "135";
Result should be a String of "270"
I have no idea how to do that...I try to make a for loop and make an addition : nb.charAt(i) + nb2.charAt(i) but with no succes, I don't know what I have to do with the carry over.
EDIT : I try to don't use Integer or BigInteger, only String this is why I try to use a for loop.
Thanks for clue.
String str = "";
// Calculate length of both String
int n1 = nb.length(), n2 = nb2.length();
int diff = n2 - n1;
// Initially take carry zero
int carry = 0;
// Traverse from end of both Strings
for (int i = n1 - 1; i>=0; i--)
{
// Do school mathematics, compute sum of
// current digits and carry
int sum = ((int)(nb.charAt(i)-'0') +
(int) nb2.charAt(i+diff)-'0') + carry);
str += (char)(sum % 10 + '0');
carry = sum / 10;
}
// Add remaining digits of nb2[]
for (int i = n2 - n1 - 1; i >= 0; i--)
{
int sum = ((int) nb2.charAt(i) - '0') + carry);
str += (char)(sum % 10 + '0');
carry = sum / 10;
}
// Add remaining carry
if (carry > 0)
str += (char)(carry + '0');
// reverse resultant String
return new StringBuilder(str).reverse().toString();
try below snippet:
String s1 = "135";
String s2 = "135";
String result = Integer.toString (Integer.parseInt(s1)+Integer.parseInt(s2));
try converting char to int using Integer.parseInt(nb.charAt(i)) + Integer.parseInt(nb2.charAt(i))
you can use Character.numericValue to give you the integer value of a character, this will probably help you write the method. This method will also return -1 if there is no numeric value or -2 if it is fractional like the character for 1/2
You need to convert the strings to numbers to add them. Let's use BigInteger, just in case the numbers are really big:
String nb = "135";
String nb2 = "135";
BigInteger num1 = new BigInteger(nb);
BigInteger num2 = new BigInteger(nb2);
String result = num1.add(num2).toString();
Do it as follows:
public class Main {
public static void main(String args[]) {
System.out.println(getSum("270", "270"));
System.out.println(getSum("3270", "270"));
System.out.println(getSum("270", "3270"));
}
static String getSum(String n1, String n2) {
StringBuilder sb = new StringBuilder();
int i, n, cf = 0, nl1 = n1.length(), nl2 = n2.length(), max = nl1 > nl2 ? nl1 : nl2, diff = Math.abs(nl1 - nl2);
for (i = max - diff - 1; i >= 0; i--) {
if (nl1 > nl2) {
n = cf + Integer.parseInt(String.valueOf(n1.charAt(i + diff)))
+ Integer.parseInt(String.valueOf(n2.charAt(i)));
} else {
n = cf + Integer.parseInt(String.valueOf(n1.charAt(i)))
+ Integer.parseInt(String.valueOf(n2.charAt(i + diff)));
}
if (n > 9) {
sb.append(n % 10);
cf = n / 10;
} else {
sb.append(n);
cf = 0;
}
}
if (nl1 > nl2) {
for (int j = i + 1; j >= 0; j--) {
sb.append(n1.charAt(j));
}
} else if (nl1 < nl2) {
for (int j = i + 1; j >= 0; j--) {
sb.append(n2.charAt(j));
}
}
return sb.reverse().toString();
}
}
Output:
540
3540
3540
I would like to propose a much cleaner solution that adds 2 positive numbers and returns the result. Just maintain a carry while adding 2 digits and add carry in the end if carry is greater than 0.
public class Main{
public static void main(String[] args) {
System.out.println(addTwoNumbers("135","135"));
}
private static String addTwoNumbers(String s1,String s2){
if(s1.length() < s2.length()) return addTwoNumbers(s2,s1);
StringBuilder result = new StringBuilder("");
int ptr2 = s2.length() - 1,carry = 0;
for(int i=s1.length()-1;i>=0;--i){
int res = s1.charAt(i) - '0' + (ptr2 < 0 ? 0 : s2.charAt(ptr2--) - '0') + carry;
result.append(res % 10);
carry = res / 10;
}
if(carry > 0) result.append(carry);
return trimLeadingZeroes(result.reverse().toString());
}
private static String trimLeadingZeroes(String str){
for(int i=0;i<str.length();++i){
if(str.charAt(i) != '0') return str.substring(i);
}
return "0";
}
}
Demo: https://onlinegdb.com/Sketpl-UL
Try this i hope it works for you
Code
public static int convert_String_To_Number(String numStr,String numStr2) {
char ch[] = numStr.toCharArray();
char ch2[] = numStr2.toCharArray();
int sum1 = 0;
int sum=0;
//get ascii value for zero
int zeroAscii = (int)'0';
for (char c:ch) {
int tmpAscii = (int)c;
sum = (sum*10)+(tmpAscii-zeroAscii);
}
for (char d:ch2) {
int tmpAscii = (int)d;
sum1 = (sum*10)+(tmpAscii-zeroAscii);
}
return sum+sum1;
}
public static void main(String a[]) {
System.out.println("\"123 + 123\" == "+convert_String_To_Number("123" , "123"));
}
}
I'm trying to find the next greatest number from the user input.If the user gives 23 it shows the output as 32.If there is number greater number then it has to print the same given number.But if the user gives 03 it shows 3 but it has to show 30.Because it takes 03 as octal number.How can i change the code to show the correct output as 30?
public class Main
{
static void swap(char ar[], int i, int j)
{
char temp = ar[i];
ar[i] = ar[j];
ar[j] = temp;
}
public static void main(String[] args)
{
Scanner in = new Scanner(System.in);
int num = in .nextInt();
char[] chars = ("" + num).toCharArray();
int i;
int n = chars.length;
for (i = n - 1; i > 0; i--)
{
if (chars[i] > chars[i - 1])
break;
}
if (i == 0)
System.out.println(num);
else {
int x = chars[i - 1], min = i;
for (int j = i + 1; j<n; j++)
{
if (chars[j] > x && chars[j]<chars[min])
min = j;
}
swap(chars, i - 1, min);
Arrays.sort(chars, i, n);
for (i = 0; i<n; i++)
System.out.print(chars[i]);
}
}
}
package com.demo;
import java.util.Arrays;
import java.util.Scanner;
public class Demo {
static void swap(char ar[], int i, int j)
{
char temp = ar[i];
ar[i] = ar[j];
ar[j] = temp;
}
public static void main(String[] args)
{
Scanner in = new Scanner(System.in);
//int num = in .nextInt();
char[] chars=null;
String numStr=in.next();
int num= Integer.valueOf(numStr);
if(numStr.startsWith("0")) {
chars= ("0" + num).toCharArray();
}else {
chars= ("" + num).toCharArray();
}
int i;
int n = chars.length;
for (i = n - 1; i > 0; i--)
{
if (chars[i] > chars[i - 1])
break;
}
if (i == 0)
System.out.println(num);
else {
int x = chars[i - 1], min = i;
for (int j = i + 1; j<n; j++)
{
if (chars[j] > x && chars[j]<chars[min])
min = j;
}
swap(chars, i - 1, min);
Arrays.sort(chars, i, n);
for (i = 0; i<n; i++)
System.out.print(chars[i]);
}
}
}
public static int findNextGreatestNumber(int[] arr, int k) {
int delta = Integer.MAX_VALUE;
int res = 0;
for (int a : arr) {
if (a - k > 0 && a - k < delta) {
delta = a - k;
res = a;
}
}
return delta == Integer.MAX_VALUE ? k : res;
}
You are reading the numbers from standard input as integers. Try reading them as strings instead:
Scanner in = new Scanner(System.in);
String num = in.nextLine();
char[] chars = num.toCharArray();
In your main(),take the input as String only, instead of taking it as integer.
String num=in.next();
I am designing a problem in which I have to use an int array to add or subtract values. For example instead of changing 100 to 101 by adding 1, I want to do the same thing using the int array. It work like this:
int[] val = new int[3];
val[0] = 1;
val[1] = 0;
val[2] = 0;
val[2] += 1;
so, If I have to get a value of 101, I will add 1 to val[2].
The only problem I have is finding a way to make int array work like how adding and subtracting from an ordinary integer data set works.
Is this possible using a for loop or a while loop?
Any help will be appreciated!
Here's your homework:
public static int[] increment(int[] val) {
for (int i = val.length - 1; i >= 0; i--) {
if (++val[i] < 10)
return val;
val[i] = 0;
}
val = new int[val.length + 1];
val[0] = 1;
return val;
}
Make sure you understand how and why it works before submitting it as your own work.
Solution of this problem is designed by using String
You can refer to this method which will return sum of 2 nos having input in String format.
Input String should contain only digits.
class Demo {
public static String add(String a1, String b1) {
int[] a = String_to_int_Array(a1);
int[] b = String_to_int_Array(b1);
int l = a.length - 1;
int m = b.length - 1;
int sum = 0;
int carry = 0;
int rem = 0;
String temp = "";
if (a.length > b.length) {
while (m >= 0) {
sum = a[l] + b[m] + carry;
carry = sum / 10;
rem = sum % 10;
temp = rem + temp;
m--;
l--;
}
while (l >= 0) {
sum = a[l] + carry;
carry = sum / 10;
rem = sum % 10;
temp = rem + temp;
l--;
}
if (carry > 0) {
temp = carry + temp;
}
} else {
while (l >= 0) {
sum = a[l] + b[m] + carry;
carry = sum / 10;
rem = sum % 10;
temp = rem + temp;
m--;
l--;
}
while (m >= 0) {
sum = b[m] + carry;
carry = sum / 10;
rem = sum % 10;
temp = rem + temp;
m--;
}
if (carry > 0) {
temp = carry + temp;
}
}
return temp;
}
public static int[] String_to_int_Array(String s) {
int arr[] = new int[s.length()], i;
for (i = 0; i < s.length(); i++)
arr[i] = Character.digit(s.charAt(i), 10);
return arr;
}
public static void main(String a[]) {
System.out.println(add("222", "111"));
}
}
Quick & dirty:
static void increment(int[] array){
int i = array.length-1;
do{
array[i]=(array[i]+1)%10;
}while(array[i--]==0 && i>=0);
}
Note the overflow when incementing e.g. {9, 9}. Result is {0, 0} here.
public static void increment() {
int[] acc = {9,9,9,9};
String s="";
for (int i = 0; i < acc.length; i++)
s += (acc[i] + "");
int i = Integer.parseInt(s);
i++;
System.out.println("\n"+i);
String temp = Integer.toString(i);
int[] newGuess = new int[temp.length()];
for (i = 0; i < temp.length(); i++)
{
newGuess[i] = temp.charAt(i) - '0';
}
printNumbers(newGuess);
}
public static void printNumbers(int[] input) {
for (int i = 0; i < input.length; i++) {
System.out.print(input[i] + ", ");
}
System.out.println("\n");
}
If someone is looking for this solution using JavaScript or if you can translate it to java, here's your optimum solution:
function incrementArr(arr) {
let toBeIncrementedFlag = 1, // carry over logic
i = arr.length - 1;
while (toBeIncrementedFlag) {
if (arr[i] === 9) {
arr[i] = 0; // setting the digit as 0 and using carry over
toBeIncrementedFlag = 1;
} else {
toBeIncrementedFlag = 0;
arr[i] += 1;
break; // Breaking loop once no carry over is left
}
if (i === 0) { // handling case of [9,9] [9,9,9] and so on
arr.unshift(1);
break;
}
i--; // going left to right because of carry over
}
return arr;
}
I'm new to java and I'm trying to see if the method public String toString() is representing correctly the polynomial function. I don't know how to give the coefficients from main so that the class Func receives them.
package ro.utcluj.poo.lab04;
import java.util.Scanner;
class Func {
public double[] coef; //the coefficients
public int nrCoef; //coefficients number
public Func(double[] input)
{
nrCoef = input.length;
this.coef = new double[nrCoef];
for (int counter = 0; counter < input.length; counter++)
coef[counter] = input[counter];
}
public double getFuncValue(double x)
{
double exponent = nrCoef;
double y = 0;
double sum = 0;
for(int i = nrCoef; i >= 0; i--)
{
y = coef[i]*Math.pow(x, exponent-1); //n grade polynomial function
exponent--;
sum += y; //the sume for each member
}
return sum;
}
public double getDerivValue(double x)
{
double deriv = 0;
double rezDeriv = 0;
for(int i = 0; i < nrCoef - 1; i++)
{
deriv = coef[i]*(nrCoef - i)*Math.pow(x, nrCoef - i -1);
rezDeriv += deriv;
}
return rezDeriv;
}
public String toString()
{
String s = new String(" ");
int exp = nrCoef-1;
for(int i = 0; i < nrCoef; i++)
{
if(exp == 0 && coef[i] > 0)
s +="+" + coef[i];
else if(exp == 0 && coef[i] < 0)
s +=coef[i];
else if(exp == 1 && coef[i] > 0 && i == 0)
s +="+" + coef[i] + "x";
else if(exp == 1 && coef[i] >0)
s +="+" + coef[i];
else if(exp == 1 && coef[i] < 0)
s+=coef[i];
else if(coef[i] == 0)
s += "";
else if(coef[i] > 0 && i!=0)
s +="+" + coef[i]+"x^" + exp;
else
s +=coef[i] + "x^" + exp;
exp--;
System.out.println(s);
}
return s;
}
}
.
public class Main04 {
public static void main(String[] args) {
double[] v = new double[]{3,5,4};
Func f = new Func(v);
}
}
If you want to see what toString() does on your object f in main, all you need to do is
System.out.println(f);
f already has the coefficients that you passed into its constructor. println will call the object's toString() method and output the resulting string for you to see.
Also, as Steven pointed out in the comments, you don't need to put:
System.out.println(s);
in your toString() method itself. toString is supposed to produce and return the string. Your main method can deal with printing it out.
It's pretty simple to see what toString() does on object f in main...
You only have to yo use :
System.out.println(f);
This method will print the result of toString() to the command line.
That's all ;)
That worked but if I give the values {-3, -5, -4} I receive this:
-3.0x^2-5.0-4.0
It's missing the x from the second term(-5.0x). That is happining only if the second value is a negative one. For positive values it's working fine.
Try this way.
class Func {
public double[] coef; // the coefficients
public int nrCoef; // coefficients number
private StringBuilder sbl = new StringBuilder();
private StringBuilder tsbl = new StringBuilder();
public Func(double[] input) {
nrCoef = input.length;
this.coef = new double[nrCoef];
sbl.append("\nF(x) = ");
int exp = 0;
for (int counter = 0; counter < nrCoef; counter++) {
coef[counter] = input[counter];
if (coef[counter] != 0) {
if (counter != 0) {
sbl.append(coef[counter] < 0 ? " - " : " + ");
} else if (coef[counter] < 0) {
sbl.append(" - ");
}
exp = nrCoef - counter - 1;
sbl.append(Math.abs(coef[counter])+(exp == 0 ? "" : exp == 1 ? "*x" : "*x^"+exp));
}
}
}
public String toString() {
return tsbl.toString().isEmpty() ? sbl.toString() : tsbl.toString();
}
public double getFuncValue(double x) {
double sum = 0;
for (int index = 0; index < nrCoef; index++) {
sum += coef[index] * Math.pow(x, nrCoef - index - 1); // n grade polynomial
}
tsbl = new StringBuilder();
tsbl.append(sbl.toString());
tsbl.append("\nF(");
tsbl.append(x);
tsbl.append(") = "+sum);
return sum;
}
...
public class CreditCardNumber {
private String issuerID = "000000";
private String accountNum = "999999999";
private int checkDigit = 0;
public CreditCardNumber(String TempissuerID, String TempaccountNum) {
if (TempissuerID != null && TempaccountNum != null
&& TempissuerID.length() == 6 && TempaccountNum.length() == 9)
if (Digits(TempissuerID) && Digits(TempaccountNum)) {
issuerID = TempissuerID;
accountNum = TempaccountNum;
calcCheckDigits();
}
}
public boolean Digits(String temp1) {
String temp = "0123456789";
int count = 0;
for (int i = 0; i < temp1.length(); i++)
for (int j = 0; j < temp.length(); j++)
if (temp1.charAt(i) == temp.charAt(j)) {
count++;
}
if (count == temp1.length()) {
return true;
}
return false;
}
public CreditCardNumber() {
}
public String getID() {
return issuerID;
}
public String getAccNum() {
return accountNum;
}
public int getDigits() {
return checkDigit;
}
private void calcCheckDigits() {
int sum;
sum = checkSum();
if ((sum + checkDigit) % 10 != 0) {
checkDigit = sum - (sum % 10);
}
System.out.printf("%d", checkDigit);
}
public void CreateCred(String TempissuerID) {
if (TempissuerID != null && TempissuerID.length() == 6
&& Digits(TempissuerID)) {
issuerID = TempissuerID;
} else {
issuerID = "000000";
}
StringBuilder TempString = new StringBuilder();
for (int i = 0; i < 9; i++) {
TempString = TempString.append((Math.random() * (9 - 0 + 1) + 0));
}
accountNum = TempString.toString();
calcCheckDigits();
}
private int checkSum() {
StringBuilder temp = new StringBuilder();
int num;
int sum = 0;
for(int i = 0 ; i <issuerID.length();i++)
{
temp = temp.append(issuerID.charAt(i));
}
for(int j = 0 ; j < accountNum.length(); j++)
{
temp = temp.append(accountNum.charAt(j));
}
System.out.println(temp);
for (int k = 0; k < temp.length(); k += 2) {
num = temp.charAt(k) - '0';
num *= 2;
if (num > 9)
num = 1 + (num % 10);
temp.setCharAt(k, (char) num);
}
for (int v = 0; v < temp.length(); v++) {
sum += temp.charAt(v) - '0';
}
System.out.printf("%d", sum);
return sum;
}
public String toString() {
String s = "";
String str = issuerID + accountNum;
return str;
}
}
I have a problem in my checksum method, I wrote some printf statement to check for the value of sum which turn out to be -930 but This is not what the value sum suppose to be , if adding only there is no reason for it to have a negative sign.I am expecting the checkDigit number to be 9 when I enter 321321 for issuerID and 654654654 for accountNum, and the value of sum in check sum will be passed to the calCheckDigits method to get the value for CheckDigit which is 9.
What am I doing wrong in this method?
ok I just edit the code now I get -30 for the sum
I just edit again my first 2 for loops in checksum was wrong leading my temp string value to be incorrect
now it get -320
still incorrect but getting better