Submission #995423

#	Time	Username	Problem	Language	Result	Execution time	Memory
995423		thinknoexit	Gondola (IOI14_gondola)	C++17	90 / 100	15 ms	2380 KiB

gondola

#include "gondola.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll MOD = 1e9 + 9;
bool ch[250500];
int p[100100];
int valid(int n, int a[]) {
    int mn = n + 1;
    int idx = 0;
    for (int i = 0;i < n;i++) {
        if (ch[a[i]]) return 0;
        ch[a[i]] = 1;
        if (a[i] <= n) {
            if (a[i] < mn) {
                mn = a[i];
                idx = i;
            }
        }
    }
    if (mn == n + 1) return 1;
    idx = (idx - mn + 1 + n) % n;
    for (int i = 0;i < n;i++) {
        if (a[(i + idx) % n] <= n && a[(i + idx) % n] != i + 1) return 0;
    }
    return 1;
}

int replacement(int n, int a[], int replacementSeq[]) {
    int mn = n + 1;
    int idx = 0;
    vector<pair<int, int>> v;
    for (int i = 0;i < n;i++) {
        if (a[i] <= n) {
            if (a[i] < mn) {
                mn = a[i];
                idx = i;
            }
        }
        else v.push_back({ a[i], i });
    }
    idx = (idx - mn + 1 + n) % n;
    for (int i = 0;i < n;i++) {
        p[(i + idx) % n] = i + 1;
    }
    int sz = 0, now = n;
    sort(v.begin(), v.end());
    for (auto& x : v) {
        while (p[x.second] != x.first) {
            replacementSeq[sz++] = p[x.second];
            p[x.second] = ++now;
        }
    }
    return sz;
}
ll mop(ll a, ll p) {
    ll ans = 1;
    for (;p != 0ll;p >>= 1ll, a = a * a % MOD) {
        if (p & 1ll) ans = ans * a % MOD;
    }
    return ans;
}
int countReplacement(int n, int a[]) {
    if (!valid(n, a)) return 0;
    int cnt = 0;
    int mx = 0;
    vector<int> v;
    for (int i = 0;i < n;i++) {
        if (a[i] > n) v.push_back(a[i]), cnt++;
        mx = max(mx, a[i]);
    }
    if (mx <= n) return 1;
    sort(v.begin(), v.end());
    int m = v.size();
    bool c = (cnt == n);
    ll ans = 1;
    int prev = n;
    for (auto& x : v) {
        ans = ans * mop(cnt, x - prev - 1) % MOD;
        cnt--;
        prev = x;
    }
    if (!c) return ans;
    return ans * n % MOD;
}

Compilation message (stderr)

gondola.cpp: In function 'int countReplacement(int, int*)':
gondola.cpp:74:9: warning: unused variable 'm' [-Wunused-variable]
   74 |     int m = v.size();
      |         ^

• 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: 0 / 10