99我

Duke 2020-03-08 10:28:06 2020-03-10 20:08:27 6

#include <bits/stdc++.h>

using namespace std;

bool ss(int a) {

if (a < 2)
return 0;


for (int i = 2; i <= a - 1; i++) {
if (a % i == 0) {
return 0;

}

return 1;

}

int main() {

int n, s = 0;
cin >> n;
for (int i = 2; i <= n; i++) {
if (ss(i)) {
s++;

}


}
cout << s << endl;

return 0;

}

超时了

90分......

yangcenyou 姜维

2023-06-04 15:36:10

@站长，不是不能发答案吗？

pikahuan 逗比

2020-03-27 16:47:03

算到根号N就行了

Duke

2020-03-14 17:37:48

3剋药

root 站长

2020-03-14 14:34:43

for (int i = 2; i <= a - 1; i++) 需要修改成 for (int i = 2; i*i <= a; i++)