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CSP-S T4
学术版参与者 4已保存回复 8
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- 此快照首次捕获于
- 2023/10/22 13:25 2 年前
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- 2023/10/22 14:17 2 年前
这怎么 T 成 40 的?
CPP#include <cstdio>
#include <iostream>
#include <vector>
#define ll long long
#define lll __int128
using namespace std;
const int N = 1e5 + 5;
int n, fa[N], id[N], buc[N], tim[N];
ll a[N], b[N], c[N], val[N];
int tp, stk[N];
vector<int> G[N];
void dfs(int u) {
for (auto v : G[u])
if (fa[u] != v) fa[v] = u, dfs(v);
}
lll calc(int id, int st, ll tot) {
if (b[id] + c[id] * st <= 1) return tot - st + 1;
if (c[id] >= 0) return (lll)b[id] * (tot - st + 1) + (lll)c[id] * (st + tot) * (tot - st + 1) / 2;
ll t = (b[id] - 1) / (-c[id]);
if (t >= tot) return (lll)b[id] * (tot - st + 1) + (lll)c[id] * (st + tot) * (tot - st + 1) / 2;;
return (lll)b[id] * (t - st + 1) + (lll)c[id] * (st + t) * (t - st + 1) / 2 + tot - t;
}
bool check(ll mid) {
for (int i = 1; i <= n; i++) buc[i] = tim[i] = 0;
for (int i = 1; i <= n; i++) {
int l = 1, r = n, res = 0;
while (l <= r) {
int Mid = l + r >> 1;
if (calc(i, Mid, mid) >= a[i]) res = Mid, l = Mid + 1;
else r = Mid - 1;
}
val[i] = res;
buc[val[i]]++;
}
for (int i = 1; i <= n; i++) buc[i] += buc[i - 1];
for (int i = n; i; i--) id[buc[val[i]]--] = i;
for (int i = 1, j = 1; i <= n; i++) {
int u = id[i];
if (tim[u]) continue;
tp = 0;
while (u && !tim[u]) stk[++tp] = u, u = fa[u];
while (tp) tim[stk[tp--]] = j++;
}
for (int i = 1; i <= n; i++)
if (tim[i] > val[i]) return false;
return true;
}
int main() {
scanf("%d", &n);
for (int i = 1; i <= n; i++) scanf("%lld %lld %lld", &a[i], &b[i], &c[i]);
for (int i = 1; i < n; i++) {
int u, v;
scanf("%d %d", &u, &v);
G[u].push_back(v), G[v].push_back(u);
}
dfs(1);
ll l = n, r = 2e18, ans = 0;
while (l <= r) {
ll mid = l + r >> 1;
if (check(mid)) ans = mid, r = mid - 1;
else l = mid + 1;
}
printf("%lld", ans);
return 0;
}
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