#include "closing.h"
#include <algorithm>
#include <set>
#include <vector>
#include <cassert>
using namespace std;
using ll = long long;
using Graph = vector<vector<pair<int,ll>>>;
void dfs(int u, int fu, const Graph& g, vector<ll>& dists, vector<int>& trace) {
for (auto [v, w] : g[u]) {
if (v == fu) continue;
assert(dists[v] < 0);
dists[v] = dists[u] + w;
trace[v] = u;
dfs(v, u, g, dists, trace);
}
}
pair<vector<ll>, vector<int>> get_dists(int u, const Graph& g) {
int n = g.size();
vector<ll> dists(n, -1);
vector<int> trace(n, -1);
dists[u] = 0;
dfs(u, -1, g, dists, trace);
return {dists, trace};
}
int no_common(ll k, const vector<ll>& dx, const vector<ll>& dy) {
vector<ll> all;
for (auto d : dx) all.push_back(d);
for (auto d : dy) all.push_back(d);
sort(all.begin(), all.end());
int cnt = 0;
for (auto d : all) {
if (d <= k) {
k -= d;
++cnt;
} else break;
}
return cnt;
}
ll f[3011][6011];
void upMin(ll& f, ll val) {
if (val < f) f = val;
}
// N <= 3000
int sub8(int n, int k,
const vector<ll>& dx, const vector<ll>& dy,
const vector<bool>& on_path) {
int res = no_common(k, dx, dy);
if (n <= 3000) {
memset(f, 0x7f, sizeof f);
f[0][0] = 0;
for (int i = 0; i < n; ++i) {
if (on_path[i]) {
for (int j = 0; j <= 2*i; ++j) {
upMin(f[i+1][j+1], f[i][j] + min(dx[i], dy[i]));
upMin(f[i+1][j+2], f[i][j] + max(dx[i], dy[i]));
}
} else {
for (int j = 0; j <= 2*i; ++j) {
f[i+1][j] = min(f[i+1][j], f[i][j]);
upMin(f[i+1][j+1], f[i][j] + min(dx[i], dy[i]));
upMin(f[i+1][j+2], f[i][j] + max(dx[i], dy[i]));
}
}
}
for (int j = 0; j <= 2*n; ++j) {
if (f[n][j] <= k) res = max(res, j);
}
}
return res;
}
int max_score(int n, int X, int Y, long long K,
vector<int> U, vector<int> V, vector<int> W) {
Graph g(n);
assert(int(U.size()) == n-1);
assert(int(V.size()) == n-1);
assert(int(W.size()) == n-1);
for (int i = 0; i < n - 1; i++) {
int u = U[i];
int v = V[i];
int w = W[i];
g[u].emplace_back(v, w);
g[v].emplace_back(u, w);
}
if (X > Y) swap(X, Y);
auto [distsX, traceX] = get_dists(X, g);
auto [distsY, traceY] = get_dists(Y, g);
vector<bool> on_path(n, false);
int cur = Y;
while (cur != X) {
on_path[cur] = true;
cur = traceX[cur];
}
on_path[X] = true;
return sub8(n, K, distsX, distsY, on_path);
}
Compilation message
closing.cpp: In function 'int sub8(int, int, const std::vector<long long int>&, const std::vector<long long int>&, const std::vector<bool>&)':
closing.cpp:59:9: error: 'memset' was not declared in this scope
59 | memset(f, 0x7f, sizeof f);
| ^~~~~~
closing.cpp:6:1: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
5 | #include <cassert>
+++ |+#include <cstring>
6 | using namespace std;
