时间机器 machine

题目大意:

给你两组区间,求覆盖问题。

对于这个问题我们可以针对每个区间的左端点进行排序,在枚举节点时,在左端点满足要求的情况下,是使右端点尽量靠近节点的右端点,使用map来优化

代码送上:

 1 #include <cstdio>
 2 #include <algorithm>
 3 #include <map>
 4 
 5 #define For(i, j, k) for(int i = j; i <= k; i++)
 6 #define y second
 7 
 8 
 9 inline int Read(){
10     char c = getchar();
11     while(c < '0' || c > '9') c = getchar();
12     int x = c - '0';
13     c = getchar();
14     while(c <= '9' && c >= '0') x = x * 10 + c - '0', c = getchar();
15     return x;
16 }
17 
18 const int N = 100010;
19 
20 using namespace std;
21 
22 typedef long long LL;
23 
24 map<int, LL> M;
25 typedef map<int, LL>::iterator it;
26 
27 struct Node{
28     int l, r, s;
29 
30     bool operator < (const Node& B) const{
31         return l < B.l;
32     }
33 }A[N], R[N];
34 
35 inline void Add(int u, int s){
36     if(!M.count(u)) M[u] = s;
37     else M[u] += s;
38 }
39 
40 int n, m;
41 
42 void check(){
43     int j = 1;
44     For(i, 1, n){
45         while(j <= m && R[j].l <= A[i].l) Add(R[j].r, R[j].s), ++j;
46         while(A[i].s){
47             it p = M.lower_bound(A[i].r);
48             if(p == M.end()){
49                 puts("No");
50                 return;
51             }
52             if(A[i].s < p -> y) p -> y -= A[i].s, A[i].s = 0;
53             else A[i].s -= p -> y, M.erase(p);
54         }
55     }
56     puts("Yes");
57 }
58 
59 int main(){
60     freopen("machine2.in", "r", stdin);
61     freopen("machine2.ans", "w", stdout);
62     int Case = Read();
63     while(Case--){
64         M.clear();
65         n = Read(), m = Read();
66         For(i, 1, n) A[i].l = Read(), A[i].r = Read(), A[i].s = Read();
67         For(i, 1, m) R[i].l = Read(), R[i].r = Read(), R[i].s = Read();
68         sort(A + 1, A + n + 1), sort(R + 1, R + m + 1);
69         check();
70     }
71     return 0;
72 }
原文地址:https://www.cnblogs.com/xxjnoi/p/7277245.html