Gym - 101350G Snake Rana——容斥

容斥裸题

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
const int maxn = 1e4 + 10;
const int INF = 0x3f3f3f3f;
int T, n, m, k;
int x[maxn], y[maxn];
int main() {
    scanf("%d", &T);
    while (T--) {
        scanf("%d %d %d", &n, &m, &k);
        for (int i = 0; i < k; i++) scanf("%d %d", &x[i], &y[i]);
        long long ans = 0;
        for (int t = 1; t < (1<<k); t++) {
            int cnt = 0, minx = INF, maxx = -INF, miny = INF, maxy = -INF;
            for (int i = 0; i < k; i++) {
                if (t & (1<<i)) {
                    cnt++;
                    minx = min(minx, x[i]);
                    maxx = max(maxx, x[i]);
                    miny = min(miny, y[i]);
                    maxy = max(maxy, y[i]);
                }
            }
            long long res = (long long)minx*(n-maxx+1)*miny*(m-maxy+1);
            if (cnt & 1) ans += res;
            else ans -= res;
        }
        cout << (long long)n*(n+1)/2*m*(m+1)/2 - ans << endl;
    }
    return 0;
}