Integer Conversion - C Language/Java

describe

Integer conversion. Write a function that determines how many bits need to be changed to convert integer A to integer B. The range of A and B is between [-2147483648, 2147483647].

Example 1:

Input: A = 29 (or 0b11101), B = 15 (or 0b01111)
Output: 2

Example 2:

Input: A = 1, B = 2

 Output: 2

Analysis: Determining how many bits need to be changed to convert integer A to integer B means that A needs to change how many binary bits to convert to B, that is, there are several binary bits in A that are different from B, and bit operations and shifts are required operation .

 C language

int convertInteger(int A, int B){

    int a=A^B;//bitwise XOR

    int count=0;

    while(a){

        if((a & 1) != 0){

            count++;//calculate the number of 1

        }

        a>>= 1;//Compared from the rightmost binary bit of a, the number of bits is shifted to the right one by one, and the leftmost sign bit is complemented

    }

    return count;

}

int main(){

    int a,b;

    scanf("%d%d",&a,&b);

    int count=convertInteger(a,b);

    printf("%d",count);

}

Java

import java.util.Scanner;
public class Solution {
    public static int convertInteger(int A, int B) {
        int a=A^B;//bitwise XOR
        int count=0;
        int i;
        for(i=31;i>=0;i--)
        {
            if(((a>>>i)&1)==1)//Shift i bits to the right, add 0 to the left
                count++;//calculate the number of 1
        }
        return count;
    }
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        int a= sc.nextInt();
        int b= sc.nextInt();
        int count=convertInteger(a,b);
        System.out.println(count);
        sc.close();
    }
}