Submission #593720

#	Time	Username	Problem	Language	Result	Execution time	Memory
593720		Valaki2	Roller Coaster Railroad (IOI16_railroad)	C++14	34 / 100	236 ms	524288 KiB

railroad

#include "railroad.h"
#include <bits/stdc++.h>
using namespace std;

#define int long long

const int inf = 1e16 + 42;

int n;
vector<int> in;
vector<int> out;
vector<vector<int> > step;
vector<vector<int> > dp;

int solve() {
    step.assign(n, vector<int> (n, 0));
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < n; j++) {
            if(i != j) {
                step[i][j] = max(out[i] - in[j], 0ll);
            }
        }
    }
    dp.assign((1 << n), vector<int> (n, inf));
    for(int mask = 1; mask < (1 << n); mask++) {
        for(int cur = 0; cur < n; cur++) {
            if(!(mask & (1 << cur))) {
                continue;
            }
            if(__builtin_popcount(mask) == 1) {
                dp[mask][cur] = 0;
                continue;
            }
            int prev_mask = mask - (1 << cur);
            for(int nei = 0; nei < n; nei++) {
                if(!(prev_mask & (1 << nei))) {
                    continue;
                }
                dp[mask][cur] = min(dp[mask][cur], dp[prev_mask][nei] + step[nei][cur]);
            }
        }
    }
    int ans = inf;
    for(int i = 0; i < n; i++) {
        ans = min(ans, dp[(1 << n) - 1][i]);
    }
    return ans;
}

int plan_roller_coaster(vector<signed> s, vector<signed> t) {
    n = (int) s.size();
    in.assign(n, 0);
    out.assign(n, 0);
    for(int i = 0; i < n; i++) {
        in[i] = s[i];
        out[i] = t[i];
    }
    return solve();
}

• Subtask 1: 11 / 11
• Subtask 2: 23 / 23
• Subtask 3: 0 / 30
• Subtask 4: 0 / 36