#include <bits/stdc++.h>
#include "sorting.h"
using namespace std;
const int _N = 2e5;
int n;
int s[_N], _s[_N];
int x[_N], y[_N];
int nxt[_N];
int t;
int viz[_N];
int Nxt[_N];
int cyc = 0;
int cycles()
{
++t;
int ret = 0;
for (int i = 0; i < n; ++i)
{
int cnt = 1;
int cur = Nxt[i];
if (viz[i] == t)
continue;
while (cur != i)
{
viz[cur] = t;
cur = Nxt[cur];
++cnt;
}
viz[cur] = t;
ret += --cnt;
}
return ret;
}
int check()
{
// return n + 1 - cyc;
++t;
int ret = 0;
for (int i = 0; i < n; ++i)
{
int cnt = 1;
int cur = Nxt[i];
if (viz[i] == t)
continue;
++ret;
while (cur != i)
{
viz[cur] = t;
cur = Nxt[cur];
}
viz[cur] = t;
}
return ret;
}
vector<pair<int, int>> ans, ans2;
void solve(int X)
{
map<int, int> vis;
for (int i = 0; i < n; ++i)
{
if (vis[i])
continue;
int cur = Nxt[i];
while (cur != i)
{
++vis[cur];
ans.push_back({i, cur});
cur = Nxt[cur];
}
++vis[cur];
}
while (ans.size() < X)
ans.push_back({0, 0});
ans2.resize(X);
for (int i = 0; i < X; ++i)
{
int rep[n + 1];
for (int j = 0; j < n; ++j)
rep[j] = j;
for (int j = i + 1; j < X; ++j)
{
swap(rep[x[j]], rep[y[j]]);
}
ans2[i] = {rep[ans[i].first], rep[ans[i].second]};
swap(rep[x[i]], rep[y[i]]);
}
for (int i = 0; i < X; ++i)
{
swap(_s[x[i]], _s[y[i]]);
swap(_s[ans2[i].first], _s[ans2[i].second]);
}
}
int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[])
{
n = N;
for (int i = 0; i < N; ++i)
{
Nxt[i] = S[i];
s[i] = S[i];
_s[i] = S[i];
}
cyc = cycles();
if (check() == 0)
return 0;
for (int i = 0; i < M; ++i)
{
x[i] = X[i];
y[i] = Y[i];
swap(s[X[i]], s[Y[i]]);
swap(Nxt[X[i]], Nxt[Y[i]]);
if (X[i] != Y[i])
{
if (Nxt[X[i]] == X[i] || Nxt[Y[i]] == Y[i])
{
++cyc;
}
else
{
--cyc;
}
}
if (check() <= i + 1)
{
solve(i + 1);
for (int j = 0; j <= i; ++j)
{
P[j] = ans2[j].first;
Q[j] = ans2[j].second;
}
return ++i;
}
}
return 0;
}
Compilation message
sorting.cpp: In function 'int check()':
sorting.cpp:45:21: warning: unused variable 'cnt' [-Wunused-variable]
45 | int cnt = 1;
| ^~~
sorting.cpp: In function 'void solve(int)':
sorting.cpp:77:27: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
77 | while (ans.size() < X)
| ~~~~~~~~~~~^~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
512 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
512 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
