Source Code
// 30. Program to display prime numbers between two intervals
// Arpan Das - CST 2nd Year (VOCLET)
#include <stdio.h>
//#include <conio.h>
//#include <stdlib.h>
void getPrimes(int, int);
void main () {
int start, end; // 1 = prime
//system("cls");
//clrscr();
printf("\t\t..:: check whether a number is prime or not ::..\n\n");
printf("please enter the starting and ending range respectively: ");
scanf("%d%d", &start, &end);
getPrimes(start, end);
//getch();
}
void getPrimes(int start, int end) {
int i, j, num, flag;
for (i=start; i<=end; i++) {
flag = 1;
if (i == 0 || i == 1) continue;
// checking each value of i
for (j=2; j<=i/2; j++) {
if (i%j == 0) {
flag = 0;
break;
}
}
if (flag==1)
printf("\n%d is a prime number.", i);
}
}
Output
..:: check whether a number is prime or not ::..
please enter the starting and ending range respectively: 1 50
2 is a prime number.
3 is a prime number.
5 is a prime number.
7 is a prime number.
11 is a prime number.
13 is a prime number.
17 is a prime number.
19 is a prime number.
23 is a prime number.
29 is a prime number.
31 is a prime number.
37 is a prime number.
41 is a prime number.
43 is a prime number.
47 is a prime number.