1 basic program

//Reverse any number using c program

#include<stdio.h>
int main(){
    int num,r,reverse=0;

    printf("Enter any number: ");
    scanf("%d",&num);

    while(num){
         r=num%10;
         reverse=reverse*10+r;
         num=num/10;
    }

    printf("Reversed of number: %d",reverse);
    return 0;
}

Sample output:
Enter any number: 12
Reversed of number: 21

//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;
}

//Write a c program to subtract two numbers without using subtraction operator

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

//FIND OUT GENERIC ROOT OF A NUMBER By C PROGRAM

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;
}

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

Meaning of generic root:
It sum of digits of a number unit we don't get a single digit. For example:
Generic root of 456: 4 + 5 + 6 = 15 since 15 is two digit numbers so 1 + 5 = 6
So, generic root of 456 = 6

//How to convert string to int without using library functions in c

#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

//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);
    }
}

Output:
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

//Program to find largest of n numbers in c

#include<stdio.h>
int main(){
  int n,num,i;
  int big;

  printf("Enter the values of n: ");
  scanf("%d",&n);

  printf("Number %d",1);
  scanf("%d",&big);

  for(i=2;i<=n;i++){
    printf("Number %d: ",i);
    scanf("%d",&num);

    if(big<num)
      big=num;
  }

  printf("Largest number is: %d",big);

  return 0;
}

Sample Output:
Enter the values of n:
Number 1: 12
Number 2: 32
Number 3: 35
Largest number is: 35

Split number into digits in c programming

Extract digits from integer in c language

#include<stdio.h>
int main(){
  int num,temp,factor=1;

  printf("Enter a number: ");
  scanf("%d",&num);

  temp=num;
  while(temp){
      temp=temp/10;
      factor = factor*10;
  }

  printf("Each digits of given number are: ");
  while(factor>1){
      factor = factor/10;
      printf("%d ",num/factor);
      num = num % factor;
  }

  return 0;
}

Sample output:
Enter a number: 123
Each digits of given number are: 1 2 3

//C program to count number of digits in a number

#include<stdio.h>
int main(){
  int num,count=0;

  printf("Enter a number: ");
  scanf("%d",&num);

  while(num){
      num=num/10;
      count++;
  }
  printf("Total digits is:  %d",count);
  return 0;
}

Sample output:

Enter a number: 23

Total digits is:  2

 Program to input time in seconds and convert them into hours, minutes and seconds and display it

#include<stdio.h>
#include<conio.h> // Linux user - Remove this

int main()
{
 /* Variable for time in second, converted in hour, converted in minutes 
 and converted in seconds, r for remainder */
 int ts, ch=0, cm=0, cs, r=0;
 
 // Inputting time in second
 printf("Enter time in seconds:");
 scanf("%d", &ts);
 
 // Converting in hours, minutes and seconds 
 if(ts<60)
 cs=ts;
 
 else if(ts<3600)
 {
 cm=ts/60;
 cs=ts%60; 
 }
 
 else if(ts>3600)
 {
 ch=ts/3600;
 r=ts%3600;
 if(r>60)
 {
  cm=r/60;
  r=r%60;
 }
 if(r<60)
 cs=r;
 }
 
 // Displaying seconds in hour, minutes and seconds
 printf("Time in hour minutes and seconds: %d/%d/%d",ch,cm,cs);
 

 getch(); // Linux user - Remove this

 return 0;
 
}