C program to find prime number from 1 to 100

C program to find prime number from 1 to 100

Output:

2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97

Implementation:

#include <stdio.h> int checkprime(int n) { int i; if(n<=1) return 0; if(n>=2 && n<=3) return 1; else if(n%2==0 || n%3==0) return 0; else { for(i=5;i*i<=n;i+=6) { if(n%i==0 || n%(i+2)==0) return 0; } return 1; } } int main(void) { int i; for(i=1;i<=100;i++) { if(checkprime(i)) { printf("%d ",i); } } return 0; }