Submission #539682

#	Time	Username	Problem	Language	Result	Execution time	Memory
539682		Eug1ena	Roller Coaster Railroad (IOI16_railroad)	C++17	34 / 100	110 ms	10708 KiB

railroad

#include <bits/stdc++.h>
using namespace std;
using lint = long long;
#define rep(i, n) for(int i = 0; i < int(n); i++)
#define rep2(i, l, n) for(int i = int(l); i < int(n); i++)
#define repr(i, n) for(int i = int(n) - 1; i >= 0; i--)
#define all(x) (x).begin(), (x).end()
inline int has(lint x, int k){ return (x >> k) & 1; };

int n;
lint a[30], b[30];
lint dp[20][1 << 16];

lint play(int at, int bit){
    if(bit == (1 << n) - 1){
        return 0;
    }
    if(dp[at][bit] != -1) return dp[at][bit];

    lint ans = 1e18;
    rep(to, n){
        if(has(bit, to)) continue;

        lint res = max(0ll, b[at] - a[to]);
        res += play(to, bit | (1 << to));

        ans = min(ans, res);
    }

    return dp[at][bit] = ans;
}

lint plan_roller_coaster(vector<int> s_in, vector<int> t_in){
    n = int(s_in.size());
    assert(n <= 16);

    rep(i, n){
        a[i] = s_in[i];
        b[i] = t_in[i];
    }
    b[n] = 1;

    memset(dp, -1, sizeof(dp));
    return play(n, 0);
}

// int main(){
//     vector<int> s{1, 4, 5, 6};
//     vector<int> t{7, 3, 8, 6};
//     cout << plan_roller_coaster(s, t) << endl;
// }

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