View Code of Problem 27

#include<stdio.h>
#include<string.h>
#include<math.h>
#include<malloc.h>
#include<string.h>
 
int isPrime(int num) {
	 int temp = num / 2;
         if(num==1)
           return 0;
	 for (int i = 2;i <= temp;i++) {
		 if (num%i == 0)
			 return 0;
	 }
	 return 1;
}
 
int main() {
	long int a, b;
	int *ab = (int *)malloc(65536 * sizeof(int));
	for (int i = 0;i <= 65535;i++)
		ab[i] = 0;
	for (int i = 1;i <= 65535;i++) {
		if (isPrime(i)) {
			ab[i]=i;
		}
	}
 
	while (scanf("%ld%ld", &a, &b)!=EOF) {
		long int sum=0;
		if (a > b) {
			int temp;
			temp=a;
			a = b;
			b = temp;
		}
		for (int i = a+1;i < b;i++) {
			if (ab[i]!=0)
				sum = sum + i;
		}
		printf("%ld\n", sum);
	}
 
 
 
 
 
}