Submission #48224

#	Time	Username	Problem	Language	Result	Execution time	Memory
48224		cheater2k	Sorting (IOI15_sorting)	C++17	36 / 100	15 ms	996 KiB

sorting

#include "sorting.h"
#include <bits/stdc++.h>
using namespace std;

const int MAXN = 2005;

int n, m;
int s[MAXN], pos[MAXN];
int cnt[MAXN];

void do_swap(int x, int y) {
	int p = s[x], q = s[y];
	swap(pos[p], pos[q]);
	swap(s[x], s[y]);
	//for (int i = 0; i < n; ++i) cerr << s[i] << ' '; cerr << endl;
}

bool is_sorted() {
	for (int i = 0; i < n; ++i) if (s[i] != i) return false;
	return true;
}

int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
	n = N;
	m = M;
  for (int i = 0; i < n; ++i) {
  	s[i] = S[i];
  	pos[s[i]] = i;
  }
  if (is_sorted()) return 0;

  for (int i = 0; i < m; ++i) {
  	++cnt[X[i]];
  	++cnt[Y[i]];
  }

  for (int i = 0; i < m; ++i) {
  	if (is_sorted()) return i;

  	do_swap(X[i], Y[i]);
  	--cnt[X[i]];
  	--cnt[Y[i]];

  	bool found = false;
  	for (int j = 0; j < n; ++j) {
  		if (pos[j] != j && cnt[j] == 0) {
  			found = true;
  			P[i] = j; Q[i] = pos[j];
  			do_swap(j, pos[j]);
  			break;
  		}
  	}

  	if (!found) P[i] = Q[i] = 0, do_swap(0, 0);
  }

  for (int i = 0; i < n; ++i) assert(s[i] == i);
  return m;
}

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