hdu1698Just a Hook（线段树区间覆盖)

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

#include <iostream>
#include<cstdio>
#include<string.h>
using namespace std;
#define max 100000
int s[max*4],te[max*4];
void pushup(int w)
{
    s[w] = s[2*w]+s[2*w+1];
}
void pushdown(int w,int m)
{
    if(te[w])
    {
        te[2*w] = te[2*w+1] = te[w];
        s[2*w] = (m-m/2)*te[w];
        s[2*w+1] = te[w]*(m/2);
        te[w] =0;
    }
}
void build(int l,int r,int w)
{
    te[w] = 0;
    if(l==r)
    {
        s[w] = 1;
        return ;
    }
    int m = (l+r)/2;
    build(l,m,2*w);
    build(m+1,r,2*w+1);
    pushup(w);
}
void update(int a,int b,int c,int l,int r,int w)
{
    if(a<=l&&b>=r)
    {
        te[w] = c;
        s[w]=c*(r-l+1);
        return ;
    }
    pushdown(w,r-l+1);
    int m = (l+r)/2;
    if(a<=m)
    update(a,b,c,l,m,2*w);
    if(b>m)
    update(a,b,c,m+1,r,2*w+1);
    pushup(w);
}
int main()
{
    int i,j,k =0 ,t,n,m,a,b,c;
    scanf("%d",&t);
    while(t--)
    {
        k++;
        scanf("%d",&n);
        build(1,n,1);
        scanf("%d",&m);
        while(m--)
        {
            scanf("%d%d%d",&a,&b,&c);
            update(a,b,c,1,n,1);
        }
        printf("Case %d: The total value of the hook is ",k);
        printf("%d.\n",s[1]);
    }
    return 0;
}