[HDOJ1698]Just a Hook（线段树，区间更新）

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

陈题，更新后查询所有叶节点的和。撸一遍模版，形成自己的风格。

#include <algorithm>
#include <iostream>
#include <iomanip>
#include <cstring>
#include <climits>
#include <complex>
#include <fstream>
#include <cassert>
#include <cstdio>
#include <bitset>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <ctime>
#include <set>
#include <map>
#include <cmath>

using namespace std;

#define fr first
#define sc second
#define pb(a) push_back(a)
#define Rint(a) scanf("%d", &a)
#define Rll(a) scanf("%I64d", &a)
#define Rs(a) scanf("%s", a)
#define FRead() freopen("in", "r", stdin)
#define FWrite() freopen("out", "w", stdout)
#define Rep(i, len) for(int i = 0; i < (len); i++)
#define For(i, a, len) for(int i = (a); i < (len); i++)
#define Cls(a) memset((a), 0, sizeof(a))
#define Full(a) memset((a), 0x7f7f, sizeof(a))

typedef struct Node {
    int lo, hi;
    Node() {}
    Node(int l, int h) : lo(l), hi(h) {}
}Node;

#define lrt rt << 1
#define rrt rt << 1 | 1
const int maxn = 100010;
int sum[maxn<<2];
int add[maxn<<2];
int n, q;

void pushUP(int rt) {
    sum[rt] = sum[lrt] + sum[rrt];
}

void pushDOWN(int rt, int m) {
    if(add[rt]) {
        add[lrt] = add[rrt] = add[rt];
        sum[lrt] = (m - (m >> 1)) * add[rrt];
        sum[rrt] = (m >> 1) * add[lrt];
        add[rt] = 0;
    }
}

void build(int l, int r, int rt) {
    add[rt] = 0;
    sum[rt] = 1;
    if(l == r) return;
    int m = (l + r) >> 1;
    build(l, m, lrt);
    build(m+1, r, rrt);
    pushUP(rt);
}

void update(int L, int R, int c, int l, int r, int rt) {
    if(l >= L && R >= r) {
        add[rt] = c;
        sum[rt] = int(c * (r - l + 1));
        return;
    }
    pushDOWN(rt, r-l+1);
    int m = (l + r) >> 1;
    int ret = 0;
    if(m >= L) update(L, R, c, l, m, lrt); 
    if(m < R) update(L, R, c, m+1, r, rrt);
    pushUP(rt);
}

int main() {
    // FRead();
    int T, _ = 1;
    int x, y, z;
    Rint(T);
    while(T--) {
        Rint(n); Rint(q);
        build(1, n, 1);
        Rep(i, q) {
            Rint(x); Rint(y); Rint(z);
            update(x, y, z, 1, n, 1);
        }
        printf("Case %d: The total value of the hook is %d.
", _++, sum[1]);
    }
    return 0;
}