Submission #759776

#	Time	Username	Problem	Language	Result	Execution time	Memory
759776		raysh07	Gondola (IOI14_gondola)	C++17	100 / 100	35 ms	5992 KiB

gondola

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

const long long mod = 1e9 + 9;

int valid(int n, int a[])
{
    set <int> st;
    for (int i = 0; i < n; i++) st.insert(a[i]);
    
    if (st.size() != n) return 0;
    
    vector <pair<int, int>> b;
    for (int i = 0; i < n; i++){
        if (a[i] <= n) b.push_back({a[i], i});
    }
    
    for (int i = 1; i < b.size(); i++){
        int need = b[i - 1].first + b[i].second - b[i - 1].second;
        if (need > n) need -= n;
        
        if (b[i].first != need) return 0;
    }
    
    return 1;
}

//----------------------

int replacement(int n, int a[], int b[])
{
    int mx = 0;
    for (int i = 0; i < n; i++) mx = max(mx, a[i]);
    
    int mn = 1e6;
    int c[n];
    for (int i = 0; i < n; i++) mn = min(mn, a[i]);
    
    if (mn > n){
        for (int i = 0; i < n; i++) c[i] = i + 1;
    } else {
        int p = -1;
        for (int i = 0; i < n; i++){
            if (a[i] <= n) p = i;
        }
        
        c[p] = a[p];
        for (int i = p + 1; i < n; i++){
            c[i] = c[i - 1] + 1;
            if (c[i] > n) c[i] = 1;
        }
        
        if (p != 0){
            c[0] = c[n - 1] + 1;
            if (c[0] > n) c[0] = 1;
            
            for (int i = 1; i < p; i++){
                c[i] = c[i - 1] + 1;
                if (c[i] > n) c[i] = 1;
            }
        }
    }
    
    int l = 0;
    set <pair<int, int>> st;
    for (int i = 0; i < n; i++){
        if (c[i] != a[i]){
            st.insert(make_pair(a[i], i));
        }
    }
    
    int repl = n + 1;
    while (st.size()){
        auto u = *st.begin();
        b[l++] = c[u.second];
        c[u.second] = repl++;
        if (c[u.second] == a[u.second]) st.erase(u);
    }
    
    return l;
}

//----------------------

long long power(long long x, int y){
    if (y==0) return 1;
    
    long long v = power(x, y/2);
    v *= v; v %= mod;
    
    if (y & 1) return v * x % mod;
    else return v;
}

int countReplacement(int n, int a[])
{
    if (!valid(n, a)) {
        return 0;
    }
    
    long long ans = n;
    vector <int> v;
    for (int i = 0; i < n; i++){
        if (a[i] <= n) ans = 1;
        else v.push_back(a[i]);
    }
    
    sort(v.begin(), v.end());
    int choices = v.size();
    int curr = n;
    for (auto x : v){
        int change = x - curr - 1;
        ans *= power(choices, change);
        ans %= mod;
        choices--;
        curr = x;
    }
    
    return (int)ans;
}

// int main(){
//     int n; cin >> n;
//     int a[n];
//     for (int i = 0; i < n; i++) cin >> a[i];
    
//     cout << countReplacement(n, a) << "\n";
//     return 0;
// }

Compilation message (stderr)

gondola.cpp: In function 'int valid(int, int*)':
gondola.cpp:12:19: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   12 |     if (st.size() != n) return 0;
      |         ~~~~~~~~~~^~~~
gondola.cpp:19:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |     for (int i = 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: 15 / 15
• Subtask 10: 10 / 10