Submission #614132

#	Time	Username	Problem	Language	Result	Execution time	Memory
614132		PiejanVDC	Shortcut (IOI16_shortcut)	C++17	0 / 100	2 ms	2688 KiB

shortcut

#include "shortcut.h"
#include <bits/stdc++.h>
using namespace std;
 
const int mxN = (int)1e5+5;

int a=-1,b=-1;
long long C;

bool ok;

vector<pair<int,long long>>adj[mxN];

pair<long long, int>search_(int u, int e = -1) {
    //cout << u << ' ';
    pair<long long, int>curr = {0, u};
    for(auto z : adj[u]) if(z.first != e && (ok || !((a == u && b == z.first && z.second == C) || (a == z.first && b == u && z.second == C)))) {
        auto X = search_(z.first, u);
        X.first += z.second;
        curr = max(curr, X);
    }
    return curr;
}

long long dfs(int u, int e = -1) {
    long long d = 0;
    for(auto z : adj[u]) if(z.first != e && (ok || !((a == u && b == z.first && z.second == C) || (a == z.first && b == u && z.second == C)))) {
        d = max(d, z.second + dfs(z.first, u));
    }
    return d;
}

long long solve() {  
    return dfs(search_(0).second);
}

long long find_shortcut(int n, vector<int>l, vector<int>d, int c) {
    for(int i = 0 ; i < n-1 ; i++) 
        adj[i].push_back({i+1, l[i]}), adj[i+1].push_back({i, l[i]}), adj[i].push_back({n+i,d[i]}), adj[n+i].push_back({i,d[i]});
    adj[n-1].push_back({n+n-1,d[n-1]});
    adj[n+n-1].push_back({n-1,d[n-1]});

    long long ans = solve();
    for(int i = 0 ; i < n ; i++) {
        for(int j = i+1 ; j < n ; j++) {
            if(i+1==j&&l[i]==c)ok=1;
            adj[i].push_back({j, c});
            adj[j].push_back({i, c});
            a = i, b = i+1, C = l[a];
            long long mx = solve(); 
            a = j-1, b = j, C = l[j-1];
            mx = max(mx, solve());
            adj[i].pop_back();
            adj[j].pop_back();
            ans = min(ans, mx);
            //cout << i << ' ' << j << ' ' << ans << '\n';
            ok=0;
        }
    }
    return ans;
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 14
• Subtask 3: 0 / 8
• Subtask 4: 0 / 7
• Subtask 5: 0 / 33
• Subtask 6: 0 / 22
• Subtask 7: 0 / 4
• Subtask 8: 0 / 3