Submission #1108679

#	Time	Username	Problem	Language	Result	Execution time	Memory
1108679		Ariadna	Gondola (IOI14_gondola)	C++14	55 / 100	17 ms	5472 KiB

gondola

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

int valid(int n, int inputSeq[]) {
    unordered_map<int, int> cnt;
    for (int i = 0; i < n; ++i) cnt[inputSeq[i]]++;
    if ((int)cnt.size() < n) return 0;
    
    for (int i = 1; inputSeq[0]+i <= n; ++i) {
        if (inputSeq[i] <= n && inputSeq[i] != inputSeq[0]+i) return 0;
    }
    
    for (int i = 1; inputSeq[0]-i > 0; ++i) {
        if (inputSeq[n-i] <= n && inputSeq[n-i] != inputSeq[0]-i) return 0;
    }
    return 1;
}
 
int replacement(int n, int gondolaSeq[], int replacementSeq[]) {
    vector<int> gondola(n);
    int idx = -1;
    for (int i = 0; i < n; ++i) {
        if (gondolaSeq[i] <= n) {
            gondola[i] = gondolaSeq[i];
            idx = i;
            break;
        }
    }
    if (idx == -1) {
        for (int i = 0; i < n; ++i) gondola[i] = i+1;
    } else {
        for (int i = 1; gondola[idx]+i <= n; ++i) {
            gondola[(idx+i)%n] = gondola[idx]+i;
        }
        for (int i = 1; gondola[idx]-i > 0; ++i) {
            gondola[(idx-i+n)%n] = gondola[idx]-i;
        }
    }
    
    vector<pair<int, int>> replacements;
    replacements.reserve(n);
    for (int i = 0; i < n; ++i) {
        if (gondolaSeq[i] != gondola[i]) replacements.push_back({gondolaSeq[i], gondola[i]});
    }
 
    sort(replacements.begin(), replacements.end());
    int l = 0, new_gondola = n+1;
    for (pair<int, int> p: replacements) {
        while (p.first > new_gondola) {
            replacementSeq[l] = p.second;
            p.second = new_gondola;
            ++new_gondola; ++l;
        } 
        replacementSeq[l] = p.second;
        ++new_gondola;
        ++l;
    }
    return l;
}

const int mod = 1e9+7;

ll mpow(ll a, int p) {
    if (p == 0) return 1;
    ll t = mpow(a, p/2);
    if (p%2) return (((t*t)%mod)*a)%mod;
    return (t*t)%mod;
}
 
int countReplacement(int n, int inputSeq[]) {
    if (!valid(n, inputSeq)) return 0;
    vector<int> g(n);
    for (int i = 0; i < n; ++i) {
        g[i] = inputSeq[i];
    }
    sort(g.begin(), g.end());
    ll ans = 1, prev = n;
    bool def_order = false;
    for (int i = 0; i < n; ++i) {
        if (g[i] <= n) {
            def_order = true;
            continue;
        }

        ans *= mpow(n-i, g[i]-prev-1);
        ans %= mod;
        prev = g[i];
    }
    if (!def_order) ans *= (long long)n;
    return ans%mod;
}

• 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: 0 / 5
• Subtask 8: 0 / 15
• Subtask 9: 0 / 15
• Subtask 10: 0 / 10