백준 7795번 먹을 것인가 먹힐 것인가 C++

https://www.acmicpc.net/problem/7795

7795번: 먹을 것인가 먹힐 것인가

 

이분탐색

 

#include <iostream>
#include <string>
#include <vector>
#include <math.h>
#include <algorithm>
#include <utility>
#include <stack>
#include <queue>
#include <math.h>
#include <set>
#include <map>
#include <list>
#include <unordered_map>
#include <unordered_set>
#include <iomanip>
#include <limits.h>

using namespace std;
using int64 = long long;

int t;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    cin >> t;
    while (t--) {
        int n, m;
        cin >> n >> m;
        vector<int> a(n);
        vector<int> b(m);
        int cnt = 0;
        for (int i = 0; i < n; i++) cin >> a[i];
        for (int i = 0; i < m; i++) cin >> b[i];
        sort(b.begin(), b.end());
        for (int i = 0; i < n; i++) {
            cnt += lower_bound(b.begin(), b.end(), a[i]) - b.begin();
        }
        cout << cnt << "\n";
    }
}