Just a Hook

code
#include<bits/stdc++.h>
#define IO ios::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#define ACM_LOCAL
using namespace std;
typedef long long ll;
const double PI = acos(-1);
const double eps = 1e-4;
const int MOD = 1e9 + 7;
const int M = 1e7 + 10;
const int N = 3e5 + 10;
struct node {
int l, r;
int sum, lazy;
}seg[N << 2];
void pushup(int rt) {
seg[rt].sum = seg[rt << 1].sum + seg[rt << 1 | 1].sum;
}
void pushdown(int rt) {
if(seg[rt].lazy) {
seg[rt << 1].lazy = seg[rt].lazy;
seg[rt << 1 | 1].lazy = seg[rt].lazy;
seg[rt << 1].sum = seg[rt].lazy * (seg[rt << 1].r - seg[rt << 1].l + 1);
seg[rt << 1 | 1].sum = seg[rt].lazy * (seg[rt << 1 | 1].r - seg[rt << 1 | 1].l + 1);
seg[rt].lazy = 0;
}
}
void build(int rt, int l, int r) {
seg[rt] = {
l, r, 1, 0};
if(l == r) {
return;
}
int mid = l + r >> 1;
build(rt << 1, l, mid);
build(rt << 1 | 1, mid + 1, r);
pushup(rt);
}
void modify(int rt, int l, int r, int x) {
if(l <= seg[rt].l && seg[rt].r <= r) {
seg[rt].sum = x * (seg[rt].r - seg[rt].l + 1);
seg[rt].lazy = x;
return ;
}
pushdown(rt);
int mid = seg[rt].l + seg[rt].r >> 1;
if(l <= mid) modify(rt << 1, l, r, x);
if(mid < r) modify(rt << 1 | 1, l, r, x);
pushup(rt);
}
int query(int rt, int l, int r) {
if(l <= seg[rt].l && seg[rt].r <= r) {
return seg[rt].sum;
}
pushdown(rt);
int mid = seg[rt].l + seg[rt].r >> 1;
int res = 0;
if(l <= mid) res += query(rt << 1, l, r);
if(mid < r) res += query(rt << 1 | 1, l, r);
return res;
}
int n, m;
int x, y, z;
void solve() {
modify(1, x, y, z);
}
int main() {
IO;
#ifdef ACM_LOCAL
freopen("input", "r", stdin);
freopen("output", "w", stdout);
#endif
int o = 1, cases = 0;
cin >> o;
while(o --) {
cout << "Case " << ++ cases << ": The total value of the hook is ";
cin >> n >> m;
build(1, 1, n);
for(int i = 1; i <= m; ++ i) {
cin >> x >> y >> z;
solve();
}
cout << query(1, 1, n) << "." << endl;
}
return 0;
}