# |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
1050002 |
2024-08-09T06:45:29 Z |
otarius |
Race (IOI11_race) |
C++17 |
|
0 ms |
0 KB |
#include <bits/stdc++.h>
#include <bits/extc++.h>
using namespace __gnu_pbds;
using namespace std;
#pragma GCC optimize("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define ff first
#define sc second
#define pb push_back
#define ll long long
#define pll pair<ll, ll>
#define pii pair<int, int>
#define ull unsigned long long
#define all(x) (x).begin(),(x).end()
#define int long long
// #define int unsigned long long
// #define ordered_set(T) tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>
// #define ordered_multiset(T) tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>
void open_file(string filename) {
freopen((filename + ".in").c_str(), "r", stdin);
freopen((filename + ".out").c_str(), "w", stdout);
}
// const ll mod = 1e9 + 7;
// const ll mod = 998244353;
const ll inf = 1e9;
const ll biginf = 1e18;
const int maxN = 5 * 1e5 + 5;
vector<pii> g[maxN];
map<int, int> dp[maxN];
int n, k, dep[maxN], sum[maxN], ans = inf;
void dfs(int v, int par, int len, int val) {
dep[v] = len; sum[v] = val;
dp[v][sum[v]] = dep[v];
for (pii u : g[v]) {
if (u.ff == par) continue;
dfs(u.ff, v, len + 1, val + u.sc);
if (dp[u.ff].size() > dp[v].size())
swap(dp[u.ff], dp[v]);
for (auto x : dp[u.ff]) {
if (dp[v].find(k + 2 * sum[v] - x.ff) != dp[v].end()) {
ans = min(ans, dp[v][k + 2 * sum[v] - x.ff] + x.sc - 2 * dep[v]);
}
} for (auto x : dp[u.ff]) {
if (dp[v].find(x.ff) == dp[v].end())
dp[v][x.ff] = x.sc;
else dp[v][x.ff] = min(dp[v][x.ff], x.sc);
}
}
}
int best_path(int _n, int _k, int h[][2], int l[]) {
n = _n; k = _k;
for (int i = 0; i < n - 1; i++) {
g[h[i][0]].pb({h[i][1], l[i]});
g[h[i][1]].pb({h[i][0], l[i]});
} dfs(0, -1, 0, 0);
return (ans == inf ? -1 : ans);
}
// int main() {
// int _n, _k;
// cin >> _n >> _k;
// int h[_n][2], l[_n];
// for (int i = 0; i < _n - 1; i++) {
// cin >> h[i][0] >> h[i][1];
// } for (int i = 0; i < _n - 1; i++) cin >> l[i];
// cout << best_path(_n, _k, h, l);
// }
Compilation message
race.cpp: In function 'void open_file(std::string)':
race.cpp:26:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
26 | freopen((filename + ".in").c_str(), "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
race.cpp:27:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
27 | freopen((filename + ".out").c_str(), "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/ccLH4YQS.o: in function `main':
grader.cpp:(.text.startup+0x28): undefined reference to `best_path(int, int, int (*) [2], int*)'
collect2: error: ld returned 1 exit status