Submission #1251622

#	Time	Username	Problem	Language	Result	Execution time	Memory
1251622		fafnir	Souvenirs (IOI25_souvenirs)	C++20	25 / 100	12 ms	412 KiB

souvenirs

#include <bits/stdc++.h>

#ifndef LOCAL
#include "souvenirs.h"
#endif 

using namespace std;


#ifdef LOCAL
vector<long long> vals;
vector<int> bought;

std::pair<std::vector<int>, long long> transaction(long long M) {

    vector<int> res;

    const int n = vals.size();
    for (int i = 0; i < n; ++i) {
        if (vals[i] <= M) {
            res.push_back(i);
            M -= vals[i];
            bought[i]++;
        }
    }
    return make_pair(res,M);
}
#endif


/*

    p[0] > p[1] > ... > p[n-1]


    ST 1:
      *) p[0] > p[1]
      *) Make transaction p[0]-1
        -> Then buying exactly one of type 1

    ST 4:
      *) p[0] > p[1] > p[2]
      *) T1: M=p[0]-1
        --> Case 1: Buying only one souvenir
            - Bought p[1]
            - C := M-p[1]  <--> p[1] = M-C
            - T2: p[1]-1

        --> Case 2: Bought 2 souvenirs
           
            M=100,
            C=11
            (M-C)/2 - 1

            100 coins, get back 11
                -> 2 souvenirs are 89
                - p[1] > p[2]
                - p[1] + p[2] = 89
                - 89 > 2*p[2]
                - 44 > p[2]
                p[2] <= 43
*/

void buy_souvenirs(int N, long long P0) {
    if (N == 2) {
        transaction(P0-1);
    } else if (N == 3) {
        long long M = P0-1;
        auto r = transaction(M);
        long long C = r.second;
        if (r.first.size() == 1) {
            transaction(M-C-1);
            transaction(M-C-1);
        } else {
            if ((M-C) % 2 == 0) {
                transaction((M-C)/2-1);
            } else {
                transaction((M-C)/2);
            }
        }
    } else {
        // Subtask 2
        for (int j = 1; j <= N-1; ++j) {
            for (int i = j; i <= N-1; ++i) {
                transaction(N-i);
            }
        }
    }
}


#ifdef LOCAL
int32_t main() {
    int tc;
    cin >> tc;
    while (tc--) {
        int n;
        cin >> n;

        bought.resize(n);
        vals.resize(n);
        for (auto& e : vals) cin >> e;
        fill_n(bought.begin(), n, 0);
        
        buy_souvenirs(n, vals[0]);

        for (int i = 0; i < 3; ++i) {
            cout << bought[i] << ' ';
        }
        cout << '\n';


    }
    return 0;
}
#endif

• Subtask 0: 0 / 0
• Subtask 1: 4 / 4
• Subtask 2: 3 / 3
• Subtask 3: 0 / 14
• Subtask 4: 18 / 18
• Subtask 5: 0 / 28
• Subtask 6: 0 / 33