Submission #1020566

#	Time	Username	Problem	Language	Result	Execution time	Memory
1020566		mansur	Shortcut (IOI16_shortcut)	C++17	0 / 100	0 ms	348 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];
ll d[N][N], msf[N], mpr[N];

long long find_shortcut(int n, vector<int> l, vector<int> dt, 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, dt[i]});
        g[i + n].push_back({i, dt[i]});
    }
    for (int i = 0; i < 2 * n; i++) {
        for (int j = 0; j < 2 * n; j++) d[i][j] = inf;
        priority_queue<pll> s;
        d[i][i] = 0;
        s.push({0, i});
        while (sz(s)) {
            auto [dt, u] = s.top();
            s.pop();
            if (-dt != d[i][u]) continue;
            for (auto [to, w]: g[u]) {
                if (d[i][to] > d[i][u] + w) {
                    d[i][to] = d[i][u] + w;
                    s.push({-d[i][to], to});
                }
            }
        }
    }
    for (int i = 0; i < n; i++) {
        for (int j = n; j <= i + n; j++) {
            mpr[i] = max(mpr[i], d[i][j]);
        }
        for (int j = i + n; j < 2 * n; j++) {
            msf[i] = max(msf[i], d[i][j]);
        }
    }
    ll ans = inf;
    for (int x = 0; x < n; x++) {
        for (int y = x + 1; y < n; y++) {
            ll res = 0;
            for (int a = n; a < 2 * n; a++) {
                if (a - n <= y) {
                    ll v = min(d[a][y], d[a][x] + c);
                    v += msf[y];
                    res = max(res, v);
                }
                if (a - n >= x) {
                    ll v = min(d[a][x], d[a][y] + c);
                    v += mpr[x];
                    res = max(res, v);    
                }
            }
            ans = min(ans, res);
        }
    }
    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