HDU-1698-Just a Hook

HDU-1698-Just a Hook

http://acm.hdu.edu.cn/showproblem.php?pid=1698

还是成段更新线段树

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#define N 100005
struct cam
{
	int x;
	int y;
	int sum;
	int val;
}list[N*4];
void build(int k,int x,int y)
{
	int mid;
	list[k].x=x;
	list[k].y=y;
	list[k].val=1;
	if(list[k].x==list[k].y)
	{
		list[k].sum=1;
		return;
	}
    mid=(x+y)/2;
	build(k<<1,x,mid);
	build(k<<1|1,mid+1,y);
	list[k].sum=list[k<<1].sum+list[k<<1|1].sum;
}
void update(int k,int x,int y,int d)
{
	int mid;
	if(list[k].x==x&&list[k].y==y)
	{
		list[k].val=d;
		list[k].sum=(list[k].y-list[k].x+1)*list[k].val;
	    return;
	}
	if(list[k].val!=0)
	{
		list[k<<1].sum=(list[k<<1].y-list[k<<1].x+1)*list[k].val;
		list[k<<1|1].sum=(list[k<<1|1].y-list[k<<1|1].x+1)*list[k].val;
		list[k<<1].val=list[k].val;
		list[k<<1|1].val=list[k].val;
		list[k].val=0;
	}
	mid=(list[k].x+list[k].y)/2;
	if(x>mid)
	update(k<<1|1,x,y,d);
	else if(y<=mid)
	update(k<<1,x,y,d);
	else
	{
		update(k<<1,x,mid,d);
		update(k<<1|1,mid+1,y,d);
	}
	list[k].sum=list[k<<1].sum+list[k<<1|1].sum;
}
int main()
{
	int t,a,b,c;
	int n,m,i;
	scanf("%d",&t);
	for(i=1;i<=t;i++)
	{
		scanf("%d",&n);
		build(1,1,n);
		scanf("%d",&m);
		while(m--)
		{
			scanf("%d %d %d",&a,&b,&c);
			update(1,a,b,c);
		}
		printf("Case %d: The total value of the hook is %d.\n",i,list[1].sum);
	}
	return 0;
}