Submission #542946

#	Time	Username	Problem	Language	Result	Execution time	Memory
542946		collodel	Gondola (IOI14_gondola)	C++17	65 / 100	23 ms	4364 KiB

gondola

#include "gondola.h"
#include <vector>
#include <iostream>
#include <algorithm>
#include <unordered_map>
using namespace std;

int valid(int n, int inputSeq[]) {
	int last = -1, invertions = 0;
	// trova l'ultimo elemento valido
	for(int i = n-1; i >= 0; --i) {
		if(inputSeq[i] <= n) {
			last = inputSeq[i];
			break;
		}
	}
	// conta le inversioni
	unordered_map<int, int> occ;
	for(int i = 0; i < n; ++i) {
		occ[inputSeq[i]]++;
		if(inputSeq[i] <= n) {
			invertions += (last > inputSeq[i]);
			last = inputSeq[i];
		}
	}

	if(invertions > 1) return false;
	// controlla non ci siano duplicati1
	return all_of(occ.begin(), occ.end(), [](pair<const int, int>& x){return x.second == 1;});
}

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

int replacement(int n, int gondolaSeq[], int replacementSeq[]) {
	// if(!valid(n, gondolaSeq)) {}
	int* mx = max_element(gondolaSeq, gondolaSeq + n);
	int k = *mx - n;
	
	// setta tutto a -1
	for(int i = 0; i < k; ++i) {
		replacementSeq[i] = -1;
	}

	// trova la posizione dell'elemento 1
	int pos = 0;
	for(int i = 0; i < n; ++i) {
		if(gondolaSeq[i] <= n) {
			pos = (n + i - gondolaSeq[i] + 1) % n;
			break;
		}
	}

	// imposta a partire da gondolaSeq
	for(int i = 0; i < n; ++i) {
		if(gondolaSeq[i] > n) {
			replacementSeq[gondolaSeq[i] - n - 1] = (n + i - pos) % n + 1;
		}
	}

	int curr_mx = (mx - gondolaSeq + n - pos) % n + 1;
	for(int i = 0; i < k; ++i) {
		if(replacementSeq[i] == -1) {
			replacementSeq[i] = curr_mx;
			curr_mx = n + i + 1;
		}
	}

	replacementSeq[*mx - n - 1] = curr_mx;

	return k;
}

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

using ll = long long;
const ll mod = 1e9 + 9ll;

ll mod_pow(ll base, ll exp) {

	ll ans = 1;
	while(exp > 0) {
		if(exp & 1) ans = (ans * base) % mod;
		exp >>= 1;
		base = (base * base) % mod;
	}

	return ans;
}

int countReplacement(int n, int inputSeq[]) {
	if(!valid(n, inputSeq)) return 0;

	ll ans = 1;

	vector<int> s;
	for(int i = 0; i < n; ++i) {
		if(inputSeq[i] > n)
			s.push_back(inputSeq[i]);
	}
	sort(s.begin(), s.end());
	int k = s.size();

	if(k == 0)
		return 1;
	ans *= mod_pow(k, s[0] - n - 1);
	ans %= mod;

	for(int i = 1; i < k; ++i) {
		ans *= mod_pow(k - i, s[i] - s[i-1] - 1);
		ans %= mod;
	}

	return ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 0 / 10
• Subtask 4: 5 / 5
• Subtask 5: 10 / 10
• Subtask 6: 20 / 20
• Subtask 7: 5 / 5
• Subtask 8: 15 / 15
• Subtask 9: 0 / 15
• Subtask 10: 0 / 10