hdu1698 Just a Hook

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

线段树，成段更新

只查询全部的和sum[1]，没写query

#include <stdio.h>

#define lson l, m, root<<1
#define rson m+1, r, root<<1|1
#define N 100100

int sum[N<<2], color[N<<2];

void push_up(int root)
{
    sum[root] = sum[root<<1] + sum[root<<1|1];
}

void push_down(int root, int x)
{
    if(color[root])
    {
        color[root<<1] = color[root<<1|1] = color[root];
        sum[root<<1] = (x-(x>>1)) * color[root];
        sum[root<<1|1] = (x>>1) * color[root];
        color[root] = 0;
    }
}

void build(int l, int r, int root)
{
    int m;
    color[root] = 0;
    if(l == r)
    {
        sum[root] = 1;
        return;
    }
    m = (l + r) >> 1;
    build(lson);
    build(rson);
    push_up(root);
}

void update(int L, int R, int x, int l, int r, int root)
{
    int m;
    if(L<=l && r<=R)
    {
        color[root] = x;
        sum[root] = (r-l+1) * x;
        return;
    }
    push_down(root, r-l+1);
    m = (l + r) >> 1;
    if(L <= m)
    {
        update(L, R, x, lson);
    }
    if(m+1 <= R)
    {
        update(L, R, x, rson);
    }
    push_up(root);
}

int main()
{
    int t, cases, n, q, x, y, z;
    scanf("%d", &t);
    for(cases=1; cases<=t && scanf("%d%d", &n, &q); cases++)
    {
        build(1, n, 1);
        while(q-- && scanf("%d%d%d", &x, &y, &z))
        {
            update(x, y, z, 1, n, 1);
        }
        printf("Case %d: The total value of the hook is %d.\n", cases, sum[1]);
    }
    return 0;
}