倾向于提高效率
#include<stdio.h> #include<math.h> int isPriNum(int num) { for(int i = 2; i <= sqrt(num); i++) { if(num%i == 0) return 0; } return 1; } int main() { int l = 0, r = 0, i = 0, sum = 0; scanf("%d%d",&l,&r); for(i = l; i <= r; i++) { if(isPriNum(i)) sum += i; } printf("%d\n",sum); return 0; }