| # | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 809128 | 2023-08-05T18:05:17 Z | OrazB | Gondola (IOI14_gondola) | C++14 | 0 ms | 0 KB |
#include <bits/stdc++.h>
// #include "gondola.h"
using namespace std;
#define all(x) (x).begin(), (x).end()
#define ll long long int
#define pii pair <int, int>
#define pb push_back
#define ff first
#define ss second
const int N = 1e5+5;
int T[N];
int valid(int n, int A[]){
map<int,int> mp;
int pos = -1;
for (int i = 0; i < n; i++){
if (mp[A[i]]++) return 0;
if (A[i] <= n){pos = i;break;}
}
if (pos == -1) return 1;
int x = A[pos];
for (int i = pos; i < n; i++){
if (i > pos and mp[A[i]]++) return 0;
if (A[i] <= n and A[i] != x) return 0;
x++;
if (x == n+1) x = 1;
}
return 1;
}
int replacement(int n, int A[], int replacementSeq[]){
int x = valid(n, A);
for (int i = 0; i < n; i++){
T[i] = i+1;
}
int pos = -1;
for (int i = 0; i < n; i++){
if (A[i] <= n){pos = i;break;}
}
if (pos != -1){
int x = A[pos];
for (int i = pos; i >= 0; i--){
T[i] = x;
x--;
if (!x) x = n;
}
x = A[pos];
for (int i = pos; i < n; i++){
T[i] = x;
x++;
if (x == n+1) x = 1;
}
}
int mx = 0, ind = 0;
map <int,int> idx;
for (int i = 0; i < n; i++){
idx[A[i]] = i+1;
if (mx < A[i]){
mx = A[i];
ind = i;
}
}
for (int i = n+1; i <= mx; i++){
if (idx[i]){
replacementSeq[i-n-1] = T[idx[i]-1];
}else{
replacementSeq[i-n-1] = T[ind];
T[ind] = i;
}
}
return mx-n;
}
const int mod = 1000000009;
int F(int x, int y){
int res = 1;
while(y){
if (y&1) res = (res*1ll*x)%mod;
x = (x*1ll*x)%mod;
y /= 2;
}
return res;
}
int countReplacement(int n, int A[]){
if (!valid(n, A)) return 0;
vector<int> vec;
int ans = 1;
for (int i = 0; i < n; i++){
if (A[i] > n) vec.pb(A[i]);
}
sort(all(vec));
int cnt = vec.size();
if (cnt == n) ans = n;
int lst = n;
for (auto i : vec){
ans = (ans*1ll*F(cnt, i-lst-1))%mod;
cmt--;
lst = i;
}
return ans;
}
int main ()
{
ios::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
int A[n];
for (int i = 0; i < n; i++) cin >> A[i];
cout << countReplacement(n, A);
}