C Program to subtract two numbers without using Minus (' - ') operator

/*perform subtraction of two integer without using Minus (" -- ") operator*/
//for positive output use if condition this code will show negative output


#include<stdio.h>


void main()
 {
          int a=10,b=20;
          while(b--) //start decrement b and also decrese a also
          {
            a-- ;
          }     
    printf("Sum of two number is=>%d",a); 
 }