原来usaco的金组题这么难。。。蒟蒻根本不会T T
我只会贪心部分，然后发现要平衡树，就不行了。。。（论线段树都写不出的蒟蒻）
然后发现
iwtwiioi的blog，Orz！原来可以用STL来做的说。。。
STL大法好！
1 /************************************************************** 2 Problem: 1691 3 User: rausen 4 Language: C++ 5 Result: Accepted 6 Time:336 ms 7 Memory:3428 kb 8 ****************************************************************/ 9 10 #include <cstdio> 11 #include <algorithm> 12 #include <set> 13 14 using namespace std; 15 typedef long long ll; 16 const int N = 100005; 17 18 struct data{ 19 int x, y; 20 }a[N], b[N]; 21 inline bool operator < (const data &a, const data &b){ 22 return a.y > b.y; 23 } 24 multiset <int> s; 25 multiset <int> :: iterator it; 26 int n, m, i, j = 1, x; 27 char ch; 28 ll ans; 29 30 inline unsigned int read(){ 31 x = 0; 32 ch = getchar(); 33 while (ch < '0' || ch > '9') 34 ch = getchar(); 35 36 while (ch >= '0' && ch <= '9'){ 37 x = x * 10 + ch - '0'; 38 ch = getchar(); 39 } 40 return x; 41 } 42 43 int main(){ 44 n = read(), m = read(); 45 for (i = 1; i <= n; ++i) 46 a[i].x = read(), a[i].y = read(); 47 for (i = 1; i <= m; ++i) 48 b[i].x = read(), b[i].y = read(); 49 sort(a + 1, a + n + 1); 50 sort(b + 1, b + m + 1); 51 for (i = 1; i <= n; ++i){ 52 while (a[i].y <= b[j].y && j <= m) 53 s.insert(b[j].x), ++j; 54 it = s.lower_bound(a[i].x); 55 if (it == s.end()){ 56 printf("-1 "); 57 return 0; 58 } 59 ans += *it; 60 s.erase(it); 61 } 62 printf("%lld ", ans); 63 return 0; 64 }
（p.s. 蒟蒻被rank1.的iwtwiioi大神稳稳地踩在了脚下）