Submission #1065139

#	Time	Username	Problem	Language	Result	Execution time	Memory
1065139		kkzyr	Gondola (IOI14_gondola)	C++17	60 / 100	31 ms	7248 KiB

gondola

#include <iostream>
#include <algorithm>
#include <map>
#include <gondola.h>
using namespace std;

const int mod = 1e9 + 7;

int input[100000];

map<int, bool> has;

int original[100001];
int index[250001];

int use_for_replacement[100000];

long long binary_exponentiation(int a, int b){
    if (b == 0){
        return 1;
    }
    long long cache = binary_exponentiation(a, b/2);
    long long ans = (cache * cache) % mod;
    if (b % 2 == 1){
        ans = (ans * a) % mod;
    }
    return ans;
}

int valid(int n, int inputSeq[]){
    for (int i = 0;i < n;i++){
        if (has[inputSeq[i]]){
            return 0;
        }
        has[inputSeq[i]] = true;
    }
    int first_original = -1;
    for (int i = 0;i < n;i++){
        if (inputSeq[i] <= n){
            first_original = i;
            break;
        }
    }
    if (first_original == -1){
        return 1;
    }
    for (int i = 0;i < n;i++){
        if (inputSeq[i] <= n){
            int diff1 = i - first_original;
            int diff2 = inputSeq[i] - inputSeq[first_original];
            if (diff2 < 0){
                diff2 += n;
            }
            if (diff1 != diff2){
                return 0;
            }
        }
    }
    return 1;
}

int replacement(int n, int gondolaSeq[], int replacementSeq[]){
    int has_index = -1;
    int max_num = -1;
    for (int i = 0;i < n;i++){
        if (gondolaSeq[i] <= n){
            has_index = i;
        }
        max_num = max(max_num, gondolaSeq[i]);
        index[gondolaSeq[i]] = i;
    }
    if (has_index == -1){
        for (int i = 0;i < n;i++){
            original[i] = i + 1;
        }
    }
    else{
        int first = gondolaSeq[has_index] - has_index;
        if (first < 0){
            first += n;
        }
        for (int i = 0;i < n;i++){
            original[i] = (first + i) % n;
            if (original[i] == 0){
                original[i] = n;
            }
        }
    }
    int length = 0;
    for (int i = n + 1;i <= max_num;i++){
        if (index[i] != 0 or gondolaSeq[0] == i){
            replacementSeq[length] = original[index[i]];
            length++;
            original[index[i]] = i;
        }
        else{
            replacementSeq[length] = original[index[max_num]];
            length++;
            original[index[max_num]] = i;
        }
    }
    return length;
}

int countReplacement(int n, int inputSeq[]){
    if (valid(n, inputSeq) == 0){
        return 0;
    }
    sort(inputSeq, inputSeq + n);
    int first_greater_n = -1;
    for (int i = 0;i < n;i++){
        if (inputSeq[i] > n){
            first_greater_n = i;
            break;
        }
    }
    if (first_greater_n == -1){
        return 1;
    }
    long long ans = binary_exponentiation(n - first_greater_n, (inputSeq[first_greater_n] - 1) - n);
    ans %= mod;
    for (int i = first_greater_n;i < (n - 1);i++){
        ans *= binary_exponentiation(n - (i + 1), (inputSeq[i + 1] - 1) - inputSeq[i]);
        ans %= mod;
    }
    return ans;
}

• 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: 0 / 15
• Subtask 9: 0 / 15
• Subtask 10: 0 / 10