前往小程序,Get更优阅读体验!
立即前往
首页
学习
活动
专区
工具
TVP
发布
社区首页 >专栏 >hdu-------(1698)Just a Hook(线段树区间更新)

hdu-------(1698)Just a Hook(线段树区间更新)

作者头像
Gxjun
发布2018-03-26 10:41:36
7370
发布2018-03-26 10:41:36
举报
文章被收录于专栏:ml

Just a Hook

Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 17124    Accepted Submission(s): 8547

Problem Description

In the game of DotA, Pudge’s meat hook is actually the most horrible thing for most of the heroes. The hook is made up of several consecutive metallic sticks which are of the same length.

Now Pudge wants to do some operations on the hook. Let us number the consecutive metallic sticks of the hook from 1 to N. For each operation, Pudge can change the consecutive metallic sticks, numbered from X to Y, into cupreous sticks, silver sticks or golden sticks. The total value of the hook is calculated as the sum of values of N metallic sticks. More precisely, the value for each kind of stick is calculated as follows: For each cupreous stick, the value is 1. For each silver stick, the value is 2. For each golden stick, the value is 3. Pudge wants to know the total value of the hook after performing the operations. You may consider the original hook is made up of cupreous sticks.

Input

The input consists of several test cases. The first line of the input is the number of the cases. There are no more than 10 cases. For each case, the first line contains an integer N, 1<=N<=100,000, which is the number of the sticks of Pudge’s meat hook and the second line contains an integer Q, 0<=Q<=100,000, which is the number of the operations. Next Q lines, each line contains three integers X, Y, 1<=X<=Y<=N, Z, 1<=Z<=3, which defines an operation: change the sticks numbered from X to Y into the metal kind Z, where Z=1 represents the cupreous kind, Z=2 represents the silver kind and Z=3 represents the golden kind.

Output

For each case, print a number in a line representing the total value of the hook after the operations. Use the format in the example.

Sample Input

1 10 2 1 5 2 5 9 3

Sample Output

Case 1: The total value of the hook is 24.

Source

2008 “Sunline Cup” National Invitational Contest

成段更新(通常这对初学者来说是一道坎),需要用到延迟标记(或者说懒惰标记),简单来说就是每次更新的时候不要更新到底,用延迟标记使得更新延迟到下次需要更新or询问到的时候 

代码:

代码语言:javascript
复制
 1 #include<cstring>
 2 #include<cstdio>
 3 const int maxn=100005;
 4 struct node
 5 {
 6     int lef,rig,sum;
 7     int cnt;
 8     int mid(){
 9       return lef+(rig-lef>>1);
10     }
11 };
12 
13 node sac[maxn*3];
14 
15 void Build(int left,int right,int pos)
16 {
17   sac[pos]=(node){left,right,1};
18   if(left==right)return ;
19   int mid=sac[pos].mid();
20   Build(left,mid,pos<<1);
21   Build(mid+1,right,pos<<1|1);
22   sac[pos].sum=sac[pos<<1].sum+sac[pos<<1|1].sum;
23 }
24 void Update(int left,int right,int pos,int val)
25 {
26    if(left<=sac[pos].lef&&sac[pos].rig<=right){
27       sac[pos].sum=val*(sac[pos].rig-sac[pos].lef+1);
28       sac[pos].cnt=val;
29       return ;
30     }
31     if(sac[pos].cnt!=0){ //向下更新一次
32       sac[pos<<1].sum=sac[pos].cnt*(sac[pos<<1].rig-sac[pos<<1].lef+1);
33       sac[pos<<1|1].sum=sac[pos].cnt*(sac[pos<<1|1].rig-sac[pos<<1|1].lef+1);
34       sac[pos<<1|1].cnt=sac[pos<<1].cnt=sac[pos].cnt;
35       sac[pos].cnt=0;
36     }
37     int mid=sac[pos].mid();
38     if(mid>=left)
39       Update(left,right,pos<<1,val);
40     if(mid<right)
41       Update(left,right,pos<<1|1,val);
42    sac[pos].sum=sac[pos<<1].sum+sac[pos<<1|1].sum;
43 }
44 int main()
45 {
46     int test,n,Q;
47     int a,b,c;
48     scanf("%d",&test);
49     for(int i=1;i<=test;i++){
50       scanf("%d%d",&n,&Q);
51       Build(1,n,1);
52       while(Q--)
53       {
54         scanf("%d%d%d",&a,&b,&c);
55         Update(a,b,1,c);
56       }
57       printf("Case %d: The total value of the hook is %d.\n",i,sac[1].sum);
58     }
59 }
本文参与 腾讯云自媒体同步曝光计划,分享自作者个人站点/博客。
原始发表:2014-08-08 ,如有侵权请联系 cloudcommunity@tencent.com 删除

本文分享自 作者个人站点/博客 前往查看

如有侵权,请联系 cloudcommunity@tencent.com 删除。

本文参与 腾讯云自媒体同步曝光计划  ,欢迎热爱写作的你一起参与!

评论
登录后参与评论
0 条评论
热度
最新
推荐阅读
目录
  • Just a Hook
领券
问题归档专栏文章快讯文章归档关键词归档开发者手册归档开发者手册 Section 归档