Submission #886112

#	Time	Username	Problem	Language	Result	Execution time	Memory
886112		VMaksimoski008	Race (IOI11_race)	C++14	0 / 100	1 ms	2484 KiB

race

#include <bits/stdc++.h>
#include "race.h"
 
#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define uniq(x) x.erase(unique(all(x)), x.end())
#define rall(x) x.rbegin(), x.rend()
//#define int long long
 
using namespace std;
 
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
 
const int mod = 1e9 + 7;
const int LOG = 20;
const int maxn = 1e5 + 5;
const double eps = 1e-9;
 
int ans = 1e9, k;
vector<vector<pii> > graph;
vector<int> dist, edges;
vector<map<int, int> > sets;

void precomp(int u, int p, int e, int d) {
    edges[u] = e;
    dist[u] = d;

    for(auto &[v, w] : graph[u]) {
        if(v == p) continue;
        precomp(v, u, e + 1, d + w);
    }
}

//dist[u] + dist[v] - 2 * dist[lca] = K;
void dfs(int u, int p) {
    sets[u][dist[u]] = edges[u];
    for(auto &[v, w] : graph[u]) {
        if(v == p) continue;
        dfs(v, u);

        if(sz(sets[u]) < sz(sets[v])) swap(sets[u], sets[v]);
        for(auto &x : sets[v])
            if(sets[v].count(k + 2 * dist[u] - x.first))
                ans = min(ans, x.second + sets[v][k+2*dist[u]-x.first] - 2 * edges[u]);
        
        for(auto &x : sets[v]) {
            if(sets[u].count(x.first)) sets[u][x.first] = min(sets[u][x.first], x.second);
            else sets[u][x.first] = x.second;
        }
    }
}
 
int best_path(int N, int K, int H[][2], int L[]) {
    k = K;
    graph.resize(N);
    dist.resize(N);
    edges.resize(N);
    sets.resize(N);
    for(int i=0; i<N-1; i++) {
        graph[H[i][0]].push_back({ H[i][1], L[i] });
        graph[H[i][1]].push_back({ H[i][0], L[i] });
    }

    precomp(0, 0, 0, 0);
    dfs(0, 0);
 
    return (ans == 1e9 ? -1 : ans);
}
 
// int32_t main() {
//     int n, k;
//     cin >> n >> k;
 
//     int g[n-1][2];
//     for(int i=0; i<n-1; i++) {
//         int a, b;
//         cin >> a >> b;
//         g[i][0] = a;
//         g[i][1] = b;
//     }
 
//     int len[n-1];
//     for(int i=0; i<n-1; i++) cin >> len[i];
 
//     cout << best_path(n, k, g, len) << '\n';
//     return 0;
// }

Compilation message (stderr)

race.cpp: In function 'void precomp(int, int, int, int)':
race.cpp:34:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   34 |     for(auto &[v, w] : graph[u]) {
      |               ^
race.cpp: In function 'void dfs(int, int)':
race.cpp:43:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   43 |     for(auto &[v, w] : graph[u]) {
      |               ^

• Subtask 1: 0 / 9
• Subtask 2: 0 / 12
• Subtask 3: 0 / 22
• Subtask 4: 0 / 57