http://acm.hdu.edu.cn/showproblem.php?pid=1698
1 10 2 1 5 2 5 9 3
Case 1: The total value of the hook is 24.
#include<stdio.h>
#include<iostream>
#define L(u) (u<<1) //u*2
#define R(u) (u<<1|1) //u*2+1
const int M=100010;
struct Node
{
int l,r;
int add,sum; //
}node[M*4];
//int a[M];
void pushdown(int u) //下分
{
node[L(u)].add=node[u].add;
node[L(u)].sum=(node[L(u)].r-node[L(u)].l+1)*node[u].add;
node[R(u)].add=node[u].add;
node[R(u)].sum=(node[R(u)].r-node[R(u)].l+1)*node[u].add;
node[u].add=0; //分完之后归0,以防出错
}
void build(int i,int left,int right)
{
node[i].l=left;
node[i].r=right;
node[i].add=0;
if(node[i].l==node[i].r)
{
node[i].sum=1;
return;
}
int mid=(node[i].l+node[i].r)/2;
build(L(i),left,mid);
build(R(i),mid+1,right);
node[i].sum=node[L(i)].sum+node[R(i)].sum;
}
void update(int u,int left,int right,int val)
{
if(left<=node[u].l&&node[u].r<=right) //建树中的区间在给出的区间内
{
node[u].add=val;
node[u].sum=(node[u].r-node[u].l+1)*val; //注意之处,这个区间的值是这么计算的
return ;
}
//node[u].sum=(right-left+1)*val;
if(node[u].add) pushdown(u); //节点的单位值不为0,下分
int mid=(node[u].l+node[u].r)/2; //建树节点(区间)的中间值
if(right<=mid) update(L(u),left,right,val); //给出的右端点(较大值)小于
else if(left>mid) update(R(u),left,right,val);//
else
{
update(L(u),left,mid,val); //跨越了两个子区间的,但是又没有完全包括的
update(R(u),mid+1,right,val);
}
node[u].sum=node[L(u)].sum+node[R(u)].sum;
}
int query(int u,int left,int right)
{
if(left<=node[u].l&&node[u].r<=right)
{
return node[u].sum;
}
if(node[u].add) pushdown(u);
int mid=(node[u].l+node[u].r)/2;
if(right<=mid) return query(L(u),left,right);
else if(left>mid) return query(R(u),left,right);
else return (query(L(u),left,mid)+query(R(u),mid+1,right));
}
int main()
{
int T,n,m,i,x,y,z;
int k=0;
scanf("%d",&T);
while(T--)
{
k++;
scanf("%d%d",&n,&m);
build(1,1,n);
for(i=0;i<m;i++)
{
scanf("%d%d%d",&x,&y,&z);
update(1,x,y,z);
}
printf("Case %d: The total value of the hook is %d.\n",k,query(1,1,n));
}
return 0;
}
杭电 1698 Just a Hook(线段树区间修改),布布扣,bubuko.com
原文地址:http://blog.csdn.net/u012766950/article/details/38510995