Question:How to add two numbers without using the plus operator in c 

#include<stdio.h>

int main(){
   
    int a,b;
    int sum;

    printf("Enter any two integers: ");
    scanf("%d%d",&a,&b);

    //sum = a - (-b);
    sum = a - ~b -1;

    printf("Sum of two integers: %d",sum);

    return 0;
}
Sample output:
Enter any two integers: 5 10
Sum of two integers: 15

Question:Write a c program or code to subtract two numbers without using subtraction operator 

#include<stdio.h>

int main(){
   
    int a,b;
    int sum;

    printf("Enter any two integers: ");
    scanf("%d%d",&a,&b);

    sum = a + ~b + 1;

    printf("Difference of two integers: %d",sum);

    return 0;
}
Sample Output:
Enter any two integers: 5 4
Difference of two integers: 1

Question:Write a c program to find largest among three numbers using binary minus operator 

#include<stdio.h>
int main(){
    int a,b,c;
    printf("\nEnter 3 numbers: ");
    scanf("%d %d %d",&a,&b,&c);
    if(a-b>0 && a-c>0)
         printf("\nGreatest is a :%d",a);
    else
         if(b-c>0)
             printf("\nGreatest is b :%d",b);
         else
             printf("\nGreatest is c :%d",c);
    return 0;
}

Question:Write a c program to find largest among three numbers using conditional operator 

#include<stdio.h>
int main(){
  int a,b,c,big;
  printf("\nEnter 3 numbers:");
  scanf("%d %d %d",&a,&b,&c);

  big=(a>b&&a>c?a:b>c?b:c);
  printf("\nThe biggest number is: %d",big);

  return 0;
}

Question:C program for generic root 

#include<stdio.h>
int main(){

long int num,sum,r;
printf("\nEnter a number:-");
scanf("%ld",&num);

while(num>10){
sum=0;
while(num){
r=num%10;
num=num/10;
sum+=r;
}
if(sum>10)
num=sum;
else
break;
}
printf("\nSum of the digits in single digit is: %ld",sum);
return 0;
}

Question:C code for calculation of generic root in one line 

#include <stdio.h>
int main(){         
int num,x;
printf("Enter any number: ");
scanf("%d",&num);
printf("Generic root: %d",(x=num%9)?x:9);
return 0;
}
Sample output:
Enter any number: 731
Generic root: 2

Question:Prime factor of a number in c 

#include<stdio.h>
int main(){
  int num,i=1,j,k;
  printf("\nEnter a number:");
  scanf("%d",&num);
  while(i<=num){
      k=0;
      if(num%i==0){
         j=1;
          while(j<=i){
            if(i%j==0)
                 k++;
             j++;
          }
          if(k==2)
             printf("\n%d is a prime factor",i);
      }
      i++;
   }
   return 0;
}

Question:Write a c program to find out NCR factor of given number 

#include<stdio.h>
int main(){
  int n,r,ncr;
  printf("Enter any two numbers->");
  scanf("%d %d",&n,&r);
  ncr=fact(n)/(fact(r)*fact(n-r));
  printf("The NCR factor of %d and %d is %d",n,r,ncr);
  return 0;
}
 int fact(int n){
  int i=1;
  while(n!=0){
      i=i*n;
      n--;
  }
  return i;
 }

Question:How to convert string to int without using library functions in c programming language 

#include<stdio.h>

int stringToInt(char[] );
int main(){
  
    char str[10];
    int intValue;

    printf("Enter any integer as a string: ");
    scanf("%s",str);

   intValue = stringToInt(str);

    printf("Equivalent integer value: %d",intValue);

    return 0;
}

int stringToInt(char str[]){
    int i=0,sum=0;

    while(str[i]!='\0'){
         if(str[i]< 48 || str[i] > 57){
             printf("Unable to convert it into integer.\n");
             return 0;
         }
         else{
             sum = sum*10 + (str[i] - 48);
             i++;
         }
    }
    return sum;
}
Sample output:
Enter any integer as a string: 123
Equivalent integer value: 123

Question:Program in c to print 1 to 100 without using loop 

#include<stdio.h>

int main(){
    int num = 1;

    print(num);

    return 0;
}
int print(num){
    if(num<=100){
         printf("%d ",num);
         print(num+1);
    }
}
Sample output:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100