题解 | 【模板】整数域二分 | 不是整体二分啊

#include <bits/stdc++.h>
using namespace std;

const int N = 2e5 + 5;
int n, q;
int a[N];

void solve() {
    cin >> n >> q;
    for (int i = 1; i <= n; i++) cin >> a[i];
    sort(a + 1, a + 1 + n);
    for (int i = 1; i <= q; i++) {
        int l, r;
        cin >> l >> r;
        auto L = lower_bound(a + 1, a + 1 + n, l);
        auto R = upper_bound(a + 1, a + 1 + n, r);
        cout << max(0, (int)(R - L)) << "\n";
    }
}

int main() {
    cin.tie(0)->sync_with_stdio(0);
    int T = 1;
    // cin >> T;
    while (T--) solve();
}
// 64 位输出请用 printf("%lld")