C program To Print All The prime numbers between 1 And N :-




Algorithm:

Step 1: start
Step 2: read n
Step 3: initialize i = 1, c = 0
Step 4:if i <= n goto step 5
            If not goto step 10
Step 5: initialize j = 1
Step 6: if j <= 1 do as the follow. If no goto step 7
            i)if i%j == 0 increment c
            ii) increment j
            iii) goto Step 6
Step 7: if c == 2 print i
Step 8: increment i
Step 9: goto step 4
Step 10: stop 

Flow Chart :-





Input & Output:

Prime no. series 
Enter any number 
10
The prime numbers between 1 to 10
2  3  5  7

C source code:-


#include<stdio.h>

#include<conio.h>

  

int main(){

  

    int N, i, j, isPrime, n;

     

    printf("To print all prime numbers between 1 to N\n");

    printf("Enter the value of N\n");

    scanf("%d",&N);

  

    /* For every number between 2 to N, check

    whether it is prime number or not */

    printf("Prime numbers between %d to %d\n", 1, N);

     

    for(i = 2; i <= N; i++){

        isPrime = 0;

        /* Check whether i is prime or not */

        for(j = 2; j <= i/2; j++){

             /* Check If any number between 2 to i/2 divides I

              completely If yes the i cannot be prime number */

             if(i % j == 0){

                 isPrime = 1;

                 break;

             }

        }

          

        if(isPrime==0 && N!= 1)

            printf("%d ",i);

    }

   getch();

   return 0;

}