Submission #674250

#	Time	Username	Problem	Language	Result	Execution time	Memory
674250		Megumin2006	Race (IOI11_race)	C++14	43 / 100	434 ms	84744 KiB

race

#include <bits/stdc++.h>

#define ll long long
#define ull unsigned long long
#define ed '\n'
#define pb push_back
#define ii pair<int,int>
#define fi first
#define se second

using namespace std;

const int N = 2e5 + 10;
ii lazy[N];
vector<ii> g[N];
int n, k, ans = 1e9;
map<int, int> f[N];

void Merge(int u, int v) {
    if (f[u].size() < f[v].size()) {
        swap(lazy[u], lazy[v]);
        f[u].swap(f[v]);
    }
    for(pair<int, int> tmp: f[v]) {
        int num = tmp.fi + lazy[v].fi;
        int Min = tmp.se + lazy[v].se;

        auto t = f[u].find(k - num - lazy[u].fi);
        if (t != f[u].end()) {
            if (t->se + Min + lazy[u].se < ans) {
                ans = t->se + Min + lazy[u].se;
            }
        }

        if (f[u][num - lazy[u].fi] == 0) f[u][num - lazy[u].fi] = Min - lazy[u].se;
        else {
            if (Min - lazy[u].se < f[u][num - lazy[u].fi]) {
                f[u][num - lazy[u].fi] = Min - lazy[u].se;
            }
        }
    }
}

void dfs(int u, int p, int val) {
    f[u][0] = 0;
    for(ii &e: g[u]) if (e.fi != p) {
        dfs(e.fi, u, e.se);
        Merge(u, e.fi);
    }
    lazy[u].fi += val;
    lazy[u].se ++;
}

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);
    if (ans == 1e9) ans = -1;
    return ans;
}

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