Submission #1251606

#	Time	Username	Problem	Language	Result	Execution time	Memory
1251606		fafnir	선물 (IOI25_souvenirs)	C++20	7 / 100	12 ms	412 KiB

souvenirs

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

/*

    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);
        } else {
            transaction((M-C)/2-1);
        }
    } 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() {

    return 0;
}
#endif

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