希望更丰富的展现？使用Markdown
by charliegong @ 2019-07-10 20:44:09
你这个问题我没看出来，但是我可以把我的代码给你
```cpp
#include <cstring>
#include <iostream>
#define N 1000001
using namespace std;
int i, j, m, n, l, r, x, p[N], ans[N];
bool ip[N];
int tot = 0;
int main(){
cin >> n >> m;
memset(ip, true, sizeof(ip));
ip[0] = ip[1] = false;
ans[1] = 0;
for(i = 2; i <= m; ++ i){
ans[i] = ans[i - 1];
if(ip[i]){
p[++ tot] = i;
ans[i] = tot;
}
for(j = 1; j <= tot && i * p[j] <= m; ++ j){
ip[i * p[j]] = false;
if(i % p[j] == 0) break;
}
}
for(i = 1; i <= n; ++ i){
cin >> l >> r;
if(l < 1 || r > m) cout << "Crossing the line";
else cout << ans[r] - ans[l - 1];
cout << endl;
}
return 0;
}
```
by 学而思李老师 @ 2019-07-10 21:02:02
请不要用Markdown语法来强调你头文件的重要性！
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by 天有不测风云 @ 2019-07-30 14:20:06