hdu 1698 线段树（成段替换 区间求和）

一条钩子由许多小钩子组成 更新一段小钩子 变成铜银金 价值分别变成1 2 3 输出最后的总价值

Sample Input
1
10
2
1 5 2
5 9 3

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

 # include <iostream>
 # include <cstdio>
 # include <cstring>
 # include <algorithm>
 # include <cmath>
 # include <queue>
 # define LL long long
 using namespace std ;

 const int maxn = ;

 int sum[maxn<<] ; //结点开4倍
 int col[maxn<<] ; //延迟标记

 void PushUP(int rt) //更新到父节点
 {
     sum[rt] = sum[rt * ] + sum[rt *  + ] ; //rt 为当前结点
 }

 void PushDown(int rt , int m )  //向下更新
 {
     if (col[rt])
     {
         col[rt * ] = col[rt *  + ] = col[rt] ;
         sum[rt * ] = (m - m / ) * col[rt] ;
         sum[rt *  + ] = (m / ) * col[rt] ;
         col[rt] =  ;
     }
 }

 void build(int l , int r , int rt) //构建线段树
 {
     col[rt] =  ;
     if (l == r)
     {
         sum[rt] =  ;
         return ;
     }
     int m = (l + r) /  ;
     build(l , m , rt * ) ;
     build(m +  , r , rt *  +) ;
     PushUP(rt) ;
 }

 void updata(int L , int R , int c , int l , int r , int rt)
 {
     if (L <= l && r <= R)
         {
             col[rt] = c ;
             sum[rt] = (r - l + ) * c ;
             return  ;
         }
     PushDown(rt , r - l + ) ;
     int m = (l + r) /  ;

     if (L <= m)
        updata(L , R , c , l , m , rt * ) ;
     if (R > m)
        updata(L , R , c , m +  , r , rt *  + ) ;

     PushUP(rt) ;
 }

 int main ()
 {
     //freopen("in.txt","r",stdin) ;
     int n , m ;
     int T ;
     int Case =  ;
     scanf("%d" , &T) ;
     while(T--)
     {
         Case++ ;
         scanf("%d%d",&n,&m);
         build( , n , ) ;
         while(m--)
         {
             int a , b , c ;
             scanf("%d%d%d",&a,&b,&c);
             updata(a , b , c ,  , n , ) ;
         }
         printf("Case %d: The total value of the hook is %d.\n",Case , sum[]);
     }

     return  ;
 }