Submission #100047

#	Time	Username	Problem	Language	Result	Execution time	Memory
100047		cheeheng	Roller Coaster Railroad (IOI16_railroad)	C++14	34 / 100	165 ms	9720 KiB

railroad

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

long long memo[18][65541];

int N;

int S[200008];
int T[200008];
typedef pair<int, int> ii;

long long dp(int cur, int state){
    if(state == 0){
        return 0;
    }else if(memo[cur][state] != -1){
        return memo[cur][state];
    }else if(cur == 17){
        long long ans = 1LL << 62;
        for(int i = 0; i < N; i ++){
            ans = min(ans, dp(i, state^(1<<i)));
        }
        return ans;
    }else{
        long long ans = 1LL << 62;
        for(int i = 0; i < N; i ++){
            if(state&(1<<i)){
                ans = min(ans, max(T[cur]-S[i], 0) + dp(i, state^(1<<i)));
            }
        }
        return memo[cur][state] = ans;
    }
}

long long plan_roller_coaster(vector<int> s, vector<int> t) {
    N = (int) s.size();
    for(int i = 0; i < N; i ++){
        S[i] = s[i];
        T[i] = t[i];
        //printf("x: %d %d\n", S[i], T[i]);
    }
    if(N > 16){
        return 0;
    }
    memset(memo, -1, sizeof(memo));
    return dp(17, (1<<N)-1);
}
/*
#include <cstdio>
#include <cassert>

int main() {
    int n;
    assert(1 == scanf("%d", &n));
    std::vector<int> s(n), t(n);
    for (int i = 0; i < n; ++i)
        assert(2 == scanf("%d%d", &s[i], &t[i]));
    long long ans = plan_roller_coaster(s, t);
    printf("%lld\n", ans);
    return 0;
}

*/

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