买菜(第14次CCF计算机软件能力认证)

link

因为是在装车的时候聊天,暴力枚举区间相交总长度即可

#include <bits/stdc++.h>

using namespace std;

#define x first
#define y second

typedef pair<int, int> PII;

const int N = 2010;

PII a[N], b[N];
int n;

int get(PII p, PII q){
    if(p.x > q.y || p.y < q.x) return 0;
    return min(p.y, q.y) - max(p.x, q.x);
}

signed main(){
    cin >> n;
    for(int i = 1; i <= n; ++i) cin >> a[i].x >> a[i].second;
    for(int i = 1; i <= n; ++i) cin >> b[i].x >> b[i].second;
    
    int res = 0;
    for(int i = 1; i <= n; ++i){
        for(int j = 1; j <= n; ++j){
            res += get(a[i], b[j]);               
        }
    }
    
    cout << res << endl;
    
    return 0;
}