Submission #431721

#	Time	Username	Problem	Language	Result	Execution time	Memory
431721		MilosMilutinovic	Gondola (IOI14_gondola)	C++14	75 / 100	45 ms	4572 KiB

gondola

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

int valid(int N, int A[]) {
    int j = -1;
    for (int i = 0; i < N; i++)
        if (A[i] >= 1 && A[i] <= N) {
            j = i;
            break;
        }

    set<int> vals;
        for (int i = 0; i < N; i++)
            vals.insert(A[i]);

    if (vals.size() != N)
        return 0;

    if (j == -1)
        return 1;

    int val = A[j];
    for (int i = 0; i < N; i++) {
        int id = (i + j) % N;

        if (A[id] >= 1 && A[id] <= N && A[id] != val)
            return 0;

        val++;
        if (val == N + 1)
            val = 1;
    }
    return 1;
}

int replacement(int N, int A[], int ans[]) {
    vector<int> B;
    for (int i = 0; i < N; i++)
        if (A[i] > N)
            B.push_back(i);

    int start_id = -1;
    for (int i = 0; i < N; i++)
        if (A[i] >= 1 && A[i] <= N) {
            start_id = i;
            break;
        }

    if (start_id == -1) {
        start_id = 0;
        for (int i = 0; i < N; i++)
            if (A[start_id] > A[i])
                start_id = i;
    }

    vector<int> start_val(N);
    for (int i = 0; i < N; i++) {
        int index = (start_id + i) % N;

        int val = (A[start_id] > N ? i + 1 : A[start_id] + i);
        if (val > N)
            val -= N;

        start_val[index] = val;
        assert(A[index] >= start_val[index]);
    }

    sort(B.begin(), B.end(), [&](int i, int j){
        return A[i] < A[j];
    });

    if (B.empty())
        return 0;

    int index = 0;

    for (int i = 0; i < (int) B.size(); i++) {
        ans[index++] = start_val[B[i]];

        if (i == 0)
            for (int j = N + 1; j < A[B[i]]; j++)
                ans[index++] = j;
        else
            for (int j = A[B[i - 1]] + 1; j < A[B[i]]; j++)
                ans[index++] = j;
    }

    return index;
}

const int MOD = 1e9 + 9;

int64_t power(int64_t x, int64_t y) {
    int64_t res = 1;
    while (y > 0) {
        if (y & 1)
            res *= x, x %= MOD;
        x *= x;
        x %= MOD;
        y >>= 1;
    }
    return res;
}

int countReplacement(int N, int A[]) {
    if (!valid(N, A))
        return 0;

    vector<int> B(1, N);
    for (int i = 0; i < N; i++)
        if (A[i] > N)
            B.push_back(A[i]);

    sort(B.begin(), B.end());

    int64_t answer = (B.size() == N + 1 ? N : 1);
    for (int i = 1, cnt = B.size() - 1; i < B.size(); i++)
        answer *= power(cnt - i + 1, B[i] - B[i - 1] - 1), answer %= MOD;

    return answer;
}

Compilation message (stderr)

gondola.cpp: In function 'int valid(int, int*)':
gondola.cpp:17:21: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   17 |     if (vals.size() != N)
      |         ~~~~~~~~~~~~^~~~
gondola.cpp: In function 'int countReplacement(int, int*)':
gondola.cpp:117:32: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  117 |     int64_t answer = (B.size() == N + 1 ? N : 1);
      |                       ~~~~~~~~~^~~~~~~~
gondola.cpp:118:43: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  118 |     for (int i = 1, cnt = B.size() - 1; i < B.size(); i++)
      |                                         ~~^~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 10 / 10
• Subtask 4: 5 / 5
• Subtask 5: 10 / 10
• Subtask 6: 20 / 20
• Subtask 7: 5 / 5
• Subtask 8: 15 / 15
• Subtask 9: 0 / 15
• Subtask 10: 0 / 10