oj.uz

Submission #48234

# Submission time Handle Problem Language Result Execution time Memory
48234 2018-05-11T02:16:43 Z cheater2k Sorting (IOI15_sorting) C++17
36 / 100
 4 ms 768 KB 
#include "sorting.h"
#include <bits/stdc++.h>
using namespace std;

const int MAXN = 200005;

int n, m;
int s[MAXN];
int pa[MAXN], pb[MAXN], a[MAXN], b[MAXN], pos[MAXN];
int x[MAXN * 3], y[MAXN * 3];
vector < pair<int,int> > vres;

bool check(int k) {
	vres.clear();
	for (int i = 0; i < n; ++i) {
		b[i] = i;
	}
	for (int i = 0; i < k; ++i) {
		swap(b[x[i]], b[y[i]]); // swap positions
	}

	// the swaps must satisfy: s[i] = b[i]
	for (int i = 0; i < n; ++i) {
		pb[s[i]] = b[i];
		pa[b[i]] = s[i];
	}

	for (int i = 0; i < n; ++i) {
		if (pa[i] != i) {
			// TODO: swap i, pb[i]
			int j = pb[i];
			int p = pa[i], q = pa[j];
			vres.push_back({p, q}); // values, not positions
			swap(pa[i], pa[j]);
			pb[q] = i;
			pb[p] = j;
		}
	}

	// trace the positions
	for (int i = 0; i < n; ++i) a[i] = s[i], pos[a[i]] = i;

	for (int i = 0; i < k; ++i) {
		// swap a[x[i]], a[y[i]]
		auto do_swap = [&](int p, int q) {
			pos[a[p]] = q;
			pos[a[q]] = p;
			swap(a[p], a[q]);
		};
		do_swap(x[i], y[i]);
		// trace
		if (i < (int)vres.size()) {
			vres[i] = {pos[vres[i].first], pos[vres[i].second]};
			do_swap(vres[i].first, vres[i].second);
		}
	}

	for (int i = (int)vres.size(); i < k; ++i) {
		vres.push_back({0, 0});
	}

	return vres.size() == k;
}

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];
  for (int i = 0; i < m; ++i) x[i] = X[i], y[i] = Y[i];

  int low = 0, high = m;
  while(low < high) {
  	int mid = ((low + high) >> 1);
  	if (check(mid)) high = mid;
  	else low = mid + 1;
  }

  check(low);
  for (int i = 0; i < low; ++i) {
  	P[i] = vres[i].first;
  	Q[i] = vres[i].second;
  }
  return low;
}

Compilation message

sorting.cpp: In function 'bool check(int)':
sorting.cpp:62:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  return vres.size() == k;
         ~~~~~~~~~~~~^~~~

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 3 ms 384 KB Output is correct
4 Correct 3 ms 384 KB Output is correct
5 Correct 3 ms 384 KB Output is correct
6 Correct 3 ms 384 KB Output is correct
7 Correct 2 ms 384 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 3 ms 384 KB Output is correct
4 Correct 3 ms 384 KB Output is correct
5 Correct 3 ms 384 KB Output is correct
6 Correct 3 ms 384 KB Output is correct
7 Correct 2 ms 384 KB Output is correct
8 Correct 3 ms 384 KB Output is correct
9 Correct 2 ms 384 KB Output is correct
10 Correct 3 ms 512 KB Output is correct
11 Correct 3 ms 384 KB Output is correct
12 Correct 3 ms 384 KB Output is correct

Subtask #3
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 384 KB Output is correct
2 Correct 3 ms 512 KB Output is correct
3 Correct 3 ms 512 KB Output is correct
4 Correct 3 ms 512 KB Output is correct
5 Correct 3 ms 512 KB Output is correct
6 Correct 2 ms 384 KB Output is correct

Subtask #4
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 384 KB Output is correct
2 Correct 2 ms 384 KB Output is correct
3 Correct 3 ms 384 KB Output is correct
4 Correct 3 ms 384 KB Output is correct
5 Correct 3 ms 384 KB Output is correct
6 Correct 3 ms 384 KB Output is correct
7 Correct 2 ms 384 KB Output is correct
8 Correct 3 ms 384 KB Output is correct
9 Correct 2 ms 384 KB Output is correct
10 Correct 3 ms 512 KB Output is correct
11 Correct 3 ms 384 KB Output is correct
12 Correct 3 ms 384 KB Output is correct
13 Correct 3 ms 384 KB Output is correct
14 Correct 3 ms 512 KB Output is correct
15 Correct 3 ms 512 KB Output is correct
16 Correct 3 ms 512 KB Output is correct
17 Correct 3 ms 512 KB Output is correct
18 Correct 2 ms 384 KB Output is correct
19 Correct 3 ms 384 KB Output is correct
20 Correct 2 ms 384 KB Output is correct
21 Incorrect 4 ms 768 KB Output isn't correct
22 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 640 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 26.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 640 KB Output isn't correct
2 Halted 0 ms 0 KB -