HDU - 1698 Just a Hook 线段树

最新推荐文章于 2022-04-01 12:15:40 发布

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最新推荐文章于 2022-04-01 12:15:40 发布

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分类专栏：线段树 HDU 文章标签： ACM 线段树

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本文介绍了一道关于计算Pudge's Hook总价值的问题。通过一系列操作改变钩子中金属棒的类型，最终求得钩子的总价值。文章提供了一个使用线段树进行区间更新的解决方案。

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Just a Hook

Time Limit: 4000/2000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 39606 Accepted Submission(s): 19194

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

Recommend

wangye

题意：告诉了每段区间钩子的值，算钩子总值为多少

#include<stdio.h>
#include<string.h>
#define MAXN 100010
struct node{
	int l,r,sum,tag;
}tree[MAXN<<2];
void build(int k,int l,int r)
{
	tree[k].l=l;tree[k].r=r;
	tree[k].tag=0;
	if(l==r)
	{
		tree[k].sum=1;
		return;
	}
	int mid=(l+r)>>1;
	build(k<<1,l,mid);
	build(k<<1|1,mid+1,r);
	tree[k].sum=tree[k<<1].sum+tree[k<<1|1].sum;
}
void pushup(int k)
{
	tree[k].sum=tree[k<<1].sum+tree[k<<1|1].sum;
}
void pushdown(int k)
{
	tree[k<<1].sum=(tree[k<<1].r-tree[k].l+1)*tree[k].tag;
	tree[k<<1|1].sum=(tree[k<<1|1].r-tree[k<<1|1].l+1)*tree[k].tag;
	tree[k<<1].tag=tree[k].tag;
	tree[k<<1|1].tag=tree[k].tag;
	tree[k].tag=0;
}
void update(int k,int l,int r,int x)
{
	if(tree[k].l==l&&tree[k].r==r)
	{
		tree[k].sum=x*(tree[k].r-tree[k].l+1);
		tree[k].tag=x;
		return;
	}
	if(tree[k].tag)
		pushdown(k);
	int mid=(tree[k].l+tree[k].r)>>1;
	if(r<=mid)
		update(k<<1,l,r,x);
	else if(l>=mid+1)
		update(k<<1|1,l,r,x);
	else
		{
			update(k<<1,l,mid,x);
			update(k<<1|1,mid+1,r,x);
		}
	pushup(k);
}
int main()
{
	int N,T,Q,X,Y,Z,cas;
	while(~scanf("%d",&T))
	{
		cas=0;
		while(T--)
		{
			scanf("%d%d",&N,&Q);
			build(1,1,N);
			while(Q--)
			{
				scanf("%d %d %d",&X,&Y,&Z);
				update(1,X,Y,Z);
			}
			printf("Case %d: The total value of the hook is %d.\n",++cas,tree[1].sum);
		}
	}
	return 0;
}