Submission #135200

#	Time	Username	Problem	Language	Result	Execution time	Memory
135200		JustasZ	Sorting (IOI15_sorting)	C++14	0 / 100	3 ms	504 KiB

sorting

/*input
5
3 0 4 2 1
5
1 1
4 0
2 3
1 4
0 4
*/
/*
5
4 3 2 1 0
6
0 1
1 2
2 3
3 4
0 1
1 2
*/
#include "sorting.h"
#include <bits/stdc++.h>
#define pb push_back
#define all(a) a.begin(), a.end()
#define sz(a) (int)a.size()
#define x first
#define y second
#define debug(...) cout << "[" << #__VA_ARGS__ << ": " << __VA_ARGS__ << "]\n"
#define rd() abs((int)rng())
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int>pii;
const int maxn = 2e5 + 100;
const int mod = 1e9 + 7;
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
int findSwapPairs(int n, int arr[], int m, int X[], int Y[], int P[], int Q[])
{
	auto chk = [&](int val) -> bool
	{
		vector<int>finalpos(n, 0), cur(n, 0);
		for(int i = 0; i < n; i++)
			cur[i] = i;
		for(int i = 0; i < val; i++)
			swap(cur[X[i]], cur[Y[i]]);
		for(int i = 0; i < n; i++)
			finalpos[cur[i]] = i;

		vector<int>where(n), v(n);
		for(int i = 0; i < n; i++)
		{
			v[i] = arr[i];
			where[v[i]] = i;
		}

		int sw = 0;
		for(int i = 0; i < n; i++)
		{
			if(finalpos[i] != v[i])
			{
				if(sw == val)
					return false;
				int pos = where[finalpos[i]];
				int was = v[i];
				swap(v[where[finalpos[i]]], v[i]);
				swap(where[finalpos[i]], where[was]);
				swap(finalpos[X[sw]], finalpos[Y[sw]]);
				swap(v[X[sw]], v[Y[sw]]);
				++sw;
			}
		}
		return true;
	};
	int l = 0, r = m;
	while(l < r)
	{
		int mid = (l + r) / 2;
		if(chk(mid))
			r = mid;
		else
			l = mid + 1; 
	}
	return l;
}
/*int main()
{
	ios_base::sync_with_stdio(false), cin.tie(0);
	int n;
	cin >> n;
	int arr[n];
	for(int i = 0; i < n; i++)
		cin >> arr[i];
	int m;
	cin >> m;
	int X[m], Y[m];
	for(int i = 0; i < m; i++)
		cin >> X[i] >> Y[i];
	int P[m], Q[m];
	cout << findSwapPairs(n, arr, m, X, Y, P, Q) << "\n";
	return 0;
}*/

Compilation message (stderr)

sorting.cpp: In lambda function:
sorting.cpp:64:9: warning: unused variable 'pos' [-Wunused-variable]
     int pos = where[finalpos[i]];
         ^~~
sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:38:68: warning: unused parameter 'P' [-Wunused-parameter]
 int findSwapPairs(int n, int arr[], int m, int X[], int Y[], int P[], int Q[])
                                                                    ^
sorting.cpp:38:77: warning: unused parameter 'Q' [-Wunused-parameter]
 int findSwapPairs(int n, int arr[], int m, int X[], int Y[], int P[], int Q[])
                                                                             ^

• Subtask 1: 0 / 8
• Subtask 2: 0 / 12
• Subtask 3: 0 / 16
• Subtask 4: 0 / 18
• Subtask 5: 0 / 20
• Subtask 6: 0 / 26