HDU 1698 Just a Hook (线段树区间更新） - c++编程基础

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 Z??http://www.2cto.com/kf/ware/vc/" target="_blank" class="keylink">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"brush:java;">1 10 2 1 5 2 5 9 3
Sample Output

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

题目意思：就是给一个n个位置（1~n）,刚开始每一个位置价值赋值为1，后来跟新一段的值例如 1 5 2 表示把1~5的位置全部变成价值为2，最后输出1~n所有位置价值和

不好理解的地方是pushdown()函数，例如输入1,n 2，我标记1到n是一样的价值（f[pos].va=1）,又输入1 3 1时，我需要吧

前面的2传递给4到n，再更新1~3

不懂就好好理解吧，都是那么苦逼过来的

#include
  
   
#include
   
     #include
    
      #include
     
       #define L(x) (x<<1) #define R(x) (x<<1|1) #define MID(x,y) ((x+y)>>1) using namespace std; #define N 100005 int a[N]; struct stud{ int le,ri; int cover; int va; }f[N*4]; void pushdown(int pos) { if(f[pos].cover) { f[L(pos)].va=f[R(pos)].va=f[pos].va; f[L(pos)].cover=f[R(pos)].cover=1; f[pos].cover=0; } } void build(int pos,int le,int ri) { f[pos].le=le; f[pos].ri=ri; f[pos].va=1; f[pos].cover=1; if(le==ri) return ; int mid=MID(le,ri); build(L(po

HDU 1698 Just a Hook (线段树区间更新）(一)