看见网上说的延迟标记，lazy标记开始有点怵头。在纸上模拟一下发现只是在区间改值之后先不急于向下更新，当访问到该结点的时候再进行更新，很巧妙的方法。
/****************************************************/
#include <iostream>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cctype>
#include <stack>
#include <map>
#include <queue>
#include <algorithm>
#include <ctime>
#define EPS 1E-8
#define MAXN 100010
#define INF (~0U >> 2)
#define MOD 1000000007
#define Lson l, mid, rt << 1
#define Rson mid + 1, r, rt << 1 | 1
using namespace std;
typedef long long LL;
/****************************************************/
int num[MAXN << 2], col[MAXN << 2];
void push_up(int rt)
{
num[rt] = num[rt << 1] + num[rt << 1 | 1];
}
void push_down(int rt, int m)
{
if (col[rt])
{
col[rt << 1] = col[rt << 1 | 1] = col[rt];
num[rt << 1] = (m - (m >> 1)) * col[rt];
num[rt << 1 | 1] = (m >> 1) * col[rt];
col[rt] = 0;
}
}
void build(int l, int r, int rt)
{
col[rt] = 0;
if (l == r)
{
num[rt] = 1;
return;
}
int mid = (l + r) >> 1;
build(Lson);
build(Rson);
push_up(rt);
}
void update(int L, int R, int c, int l, int r, int rt)
{
if (L <= l && r <= R)
{
col[rt] = c;
num[rt] = (r - l + 1) * c;
return;
}
push_down(rt, r - l + 1);
int mid = (l + r) >> 1;
if (L <= mid)
update(L, R, c, Lson);
if (R > mid)
update(L, R, c, Rson);
push_up(rt);
}
int main()
{
int t, now = 0;
scanf("%d", &t);
while (t--)
{
int n;
scanf("%d", &n);
build(1, n, 1);
int q;
scanf("%d", &q);
while(q--)
{
int a, b, c;
scanf("%d%d%d", &a, &b, &c);
update(a, b, c, 1, n, 1);
}
printf("Case %d: The total value of the hook is %d.\n", ++now, num[1]);
}
}