Submission #1020528

#	Time	Username	Problem	Language	Result	Execution time	Memory
1020528		mansur	Shortcut (IOI16_shortcut)	C++17	0 / 100	2029 ms	464 KiB

shortcut

#include "shortcut.h"
#include <bits/stdc++.h>

using namespace std;

#define rall(s) s.rbegin(), s.rend()
#define all(s) s.begin(), s.end()
#define sz(s) (int)s.size()
#define s second 
#define f first 

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

const ll inf = 1e18, N = 1000;

vector<pll> g[N];

pll fnd(int x, int n) {
    priority_queue<pll> s;
    vector<ll> d(n, inf);
    d[x] = 0;
    s.push({0, x});
    int mx = x;
    while (sz(s)) {
        auto [dt, u] = s.top();
        s.pop();
        if (-dt != d[u]) continue;
        if (d[u] > d[mx]) mx = u;
        for (auto [to, w]: g[u]) {
            if (d[to] > d[u] + w) {
                d[to] = d[u] + w;
                s.push({-d[to], to});
            }
        }
    }
    return {mx, d[mx]};
}

ll f(int n) {
    ll res = 0;
    for (int i = n / 2; i < n; i++) {
        res = max(res, fnd(i, n).s);
    }
    return res;
}

long long find_shortcut(int n, vector<int> l, vector<int> d, int c) {
    for (int i = 0; i < n - 1; i++) {
        g[i].push_back({i + 1, l[i]});
        g[i + 1].push_back({i, l[i]});
    }
    for (int i = 0; i < n; i++) {
        g[i].push_back({i + n, d[i]});
        g[i + n].push_back({i, d[i]});
    }
    ll ans = inf;
    for (int x = 0; x < n; x++) {
        for (int y = x + 1; y < n; y++) {
            g[x].push_back({y, c});
            g[y].push_back({x, c});
            ans = min(ans, f(2 * n));
            g[x].pop_back();
            g[y].pop_back();
        }
    }
    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