C Program to Find Ones Complement of a Binary Number

  • Write a C program to read a binary number and print its ones complement.
  • Wap in C to find ones complement of a binary number.

Required Knowledge

Algorithm to find ones complement of a binary number
  • To find the ones complement of a number, we will toggle the bits of the number. Change all 1's to 0's and all 0's to 1's.

For Example :
Binary Number = 00101011
Ones Complement = 11010100


C program to find ones complement of a number

#include <stdio.h>  
#include <string.h>  
  
int main() {
    char binaryNumber[100], onesComplement[100];  
    int counter, error=0, digitCount;  
  
    /*
     * Take a binary string as input from user
     */
    printf("Enter a Binary Number\n");  
    scanf("%s", binaryNumber);  
  
    /* 
     * To get one's complement, we toggle 
     * 1's to 0's and 0's to 1's
     */
    digitCount = strlen(binaryNumber);
    
 for(counter=0; counter < digitCount; counter++) {  
        if(binaryNumber[counter]=='1') {  
            onesComplement[counter] = '0';  
        } else if(binaryNumber[counter]=='0') {  
            onesComplement[counter] = '1';  
        } else {  
            printf("Error :( ");  
            return 1;
        }  
    }  
    onesComplement[digitCount] = '\0';
      
    printf("Ones Complement : %s", onesComplement);  
  
    return 0;  
} 

Output
Enter a Binary Number
11110010101
Ones Complement : 00001101010
Enter a Binary Number
10001111
Ones Complement : 01110000

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