51nod 1672 区间交（贪心）

 1 #include<iostream>
 2 #include<algorithm>
 3 #include<cstring>
 4 #include<cstdio>
 5 #include<vector>
 6 #include<stack>
 7 #include<queue>
 8 #include<cmath>
 9 #include<map>
10 #include<set>
11 using namespace std;
12 typedef long long ll;
13 typedef pair<int,int> pll;
14 const int INF = 0x3f3f3f3f;
15 const int maxn = 100000+5;
16 
17 int n,k,m;
18 int a[maxn];
19 ll sum[maxn];
20 
21 priority_queue< int,vector<int>,greater<int> > q;
22 
23 struct node
24 {
25     int left, right;
26     bool operator< (const node& rhs) const
27     {
28         return left<rhs.left||(left==rhs.left && right<rhs.right);
29     }
30 }p[maxn];
31 
32 int main()
33 {
34     //freopen("in.txt","r",stdin);
35     while(~scanf("%d%d%d",&n,&k,&m))
36     {
37         sum[0]=0;
38         for(int i=1;i<=n;i++)
39         {
40             scanf("%d",&a[i]);
41             sum[i]=sum[i-1]+a[i];
42         }
43         for(int i=0;i<m;i++)
44             scanf("%d%d",&p[i].left,&p[i].right);
45         sort(p,p+m);
46         while(!q.empty())  q.pop();
47         ll ans=0;
48         for(int i=0;i<m;i++)
49         {
50             q.push(p[i].right);
51             if(q.size()==k)
52             {
53                 ans=max(ans,sum[q.top()]-sum[p[i].left-1]);
54                 q.pop();
55             }
56         }
57         printf("%lld\n",ans);
58     }
59     return 0;
60 }