Submission #1116688

#	Time	Username	Problem	Language	Result	Execution time	Memory
1116688		NotLinux	Roller Coaster Railroad (IOI16_railroad)	C++17	34 / 100	129 ms	14356 KiB

railroad

#include "railroad.h"
#include <bits/stdc++.h>
using namespace std;
const long long inf = 1e18 + 7;
long long plan_roller_coaster(std::vector<int> s, std::vector<int> t) {
    int n = (int) s.size();
    if(n <= 16){
        long long dp[n][1 << n];
        for(int i = 0;i<n;i++)for(int j = 0;j<(1<<n);j++)dp[i][j] = inf;
        dp[0][0] = 0;
        long long ans = inf;
        for(int j = 0;j<(1<<n);j++){
            for(int i = 0;i<n;i++){
                if(j == ((1<<n)-1)){
                    ans = min(ans , dp[i][j]);
                }
                for(int k = 0;k<n;k++){
                    if((j & (1 << k)) == 0){
                        int cost = max(0 , t[i] - s[k]);
                        if(j == 0)cost = 0;
                        dp[k][j | (1 << k)] = min(dp[k][j | (1 << k)] , dp[i][j] + 1ll * cost);
                    }
                }
            }
        }
        return ans;
    }
    pair < int , int > arr[n];
    for(int i = 0;i<n;i++)arr[i] = {t[i] , s[i]};
    sort(arr , arr + n);
    multiset < pair < int , int > > ste;
    for(int i = 0;i<n;i++)ste.insert({s[i] , t[i]});
    int sayac = 0;
    for(int i = n-1;i>=0;i--){
        auto it = ste.lower_bound({arr[i].first , 0});
        if(it == ste.end()){
            // cout << "failed " << arr[i].second << " " << arr[i].first << endl;
            sayac++;
        }
        else{
            if(*it == make_pair(arr[i].second , arr[i].first)){
                // cout << "failed " << arr[i].second << " " << arr[i].first << endl;
                ++it;
            }

            if(it == ste.end())sayac++;
            else {
                // cout << arr[i].second << " " << arr[i].first << " -> " << (*it).first << " " << (*it).second << endl;
                ste.erase(it);
            }
        }
    }
    return sayac <= 1;
}

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