Submission #106692

#	Time	Username	Problem	Language	Result	Execution time	Memory
106692		tincamatei	Gondola (IOI14_gondola)	C++14	75 / 100	28 ms	2296 KiB

gondola

#include "gondola.h"
#include <bits/stdc++.h>

using namespace std;

const int MAX_N = 100000;
const int MOD = 1000000009;

int valid(int n, int inputSeq[]) {
	int fixed = -1;

	vector<int> aux(MAX_N, 0);

	for(int i = 0; i < n; ++i)
		if(inputSeq[i] <= n)
			fixed = i;
	
	for(int i = 0; i < n; ++i)
		aux[i] = inputSeq[i];
	
	sort(aux.begin(), aux.begin() + n);
	for(int i = 0; i < n - 1; ++i) // All gondolas must be distinct
		if(aux[i] == aux[i + 1])
			return false;

	if(fixed == -1) // All gondolas have been replaced
		return true;
	
	for(int i = 0; i < n; ++i) {
		int expected = (inputSeq[fixed] + i - 1) % n + 1;
		int expectedPos = (fixed + i) % n;
		if(!(inputSeq[expectedPos] == expected || inputSeq[expectedPos] > n))
			return false;
	}
	return true;
}

int replacement(int n, int gondolaSeq[], int replacementSeq[]) {
	int top = 0, lastVal = n;
	int fixed = -1;

	vector<pair<int, int> > aux;

	for(int i = 0; i < n; ++i) {
		if(gondolaSeq[i] > n)
			aux.push_back(make_pair(gondolaSeq[i], i));
		else
			fixed = i;
	}

	sort(aux.begin(), aux.end());

	for(auto it: aux) {
		int expectedVal;
		if(fixed != -1)
			expectedVal = (gondolaSeq[fixed] + it.second - fixed + 2 * n - 1) % n + 1;
		else
			expectedVal = it.second + 1;
		
		replacementSeq[top++] = expectedVal;
		++lastVal;
		
		while(lastVal < it.first) {
			replacementSeq[top++] = lastVal;
			lastVal++;
		}
	}

	return top;
}

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

int lgputm(int a, int b) {
	int ac = 1;
	while(b > 0) {
		if(b % 2 == 1)
			ac = (long long)ac * a % MOD;
		a = (long long)a * a % MOD;
		b /= 2;
	}
	return ac;
}

int countReplacement(int n, int inputSeq[]) {
	if(!valid(n, inputSeq)) // ayyyy lmao
		return 0;
	
	int rez = 1, rem, lastVal = n;

	vector<int> aux;

	for(int i = 0; i < n; ++i)
		if(inputSeq[i] > n)
			aux.push_back(inputSeq[i]);

	sort(aux.begin(), aux.end());
	rem = aux.size();

	for(auto it: aux) {
		rez = (long long)rez * lgputm(rem, it - lastVal - 1) % MOD;
		lastVal = it;
		rem--;
	}

	return rez;
}

• 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: 0 / 15
• Subtask 10: 0 / 10