I - Defeat the Enemy UVALive - 7146 二分 + 贪心

#include <bits/stdc++.h>
#define IOS ios::sync_with_stdio(false)
using namespace std;
#define inf (0x3f3f3f3f)
typedef long long int LL;
const int maxn = 1e5 + 20;
struct Node {
    int a, b;
}one[maxn], two[maxn];
bool cmp1(Node a, Node b) {
    if (a.a != b.a) return a.a > b.a;
    else return a.b < b.b;
}
bool cmp2(Node a, Node b) {
    if (a.b != b.b) return a.b > b.b;
    else return a.a > b.a;
}
multiset< int > ss;
int f;
void work() {
    ss.clear();
    int n, m;
    scanf("%d%d", &n, &m);
    for (int i = 1; i <= n; ++i) {
        scanf("%d%d", &one[i].a, &one[i].b);
    }
    for (int i = 1; i <= m; ++i) {
        scanf("%d%d", &two[i].a, &two[i].b);
    }
    sort(one + 1, one + 1 + n, cmp1);
    sort(two + 1, two + 1 + m, cmp2);
    int ans = n;
    multiset< int > :: iterator it;
    if (n < m || one[1].a < two[1].b) {
        ans = -1;
    } else {
        int p = 1;
        for (int i = 1; i <= m; ++i) {
            while (p <= n && one[p].a >= two[i].b) {
                ss.insert(one[p].b);
                p++;
            }
            if (ss.empty()) {
                ans = -1;
                break;
            }
            it = ss.upper_bound(two[i].a);
            if (it == ss.end()) {
                it = ss.begin();
                ss.erase(it);
                ans--;
            } else {
                ss.erase(it);
            }
        }
    }
    printf("Case #%d: %d\n", ++f, ans);
}

int main() {
#ifdef local
    freopen("data.txt", "r", stdin);
//    freopen("data.txt", "w", stdout);
#endif
    int t;
    scanf("%d", &t);
    while (t--) work();
    return 0;
}