// Online C++ Compiler - Build, Compile and Run your C++ programs online in your favorite browser
#include<iostream>
#include<vector>
#include<queue>
#include<algorithm>
using namespace std;
void testcase() {
int n;
cin >> n;
vector <int> A(n), AS(n);
for (int i = 0; i < n; i++) {
cin >> A[i];
AS[i] = A[i];
}
sort(AS.begin(), AS.end());
for (int i = 0; i < n; i++) {
A[i] = lower_bound(AS.begin(), AS.end(), A[i]) - AS.begin();
}
vector < deque <int> > Ans;
vector <int> Last_it(n, -1);
for (int it = 0; ; it++) {
deque <int> Cur_row;
for (int i = 0; i < n; i++) {
int ai = A[i];
if (A[i] == i || Last_it[i] == it || Last_it[ai] == it) {
continue;
}
Last_it[i] = it;
Last_it[ai] = it;
swap(A[i], A[ai]);
Cur_row.push_front(i);
Cur_row.push_back(ai);
}
if (!Cur_row.empty()) {
Ans.push_back(Cur_row);
}
else {
break;
}
}
cout << Ans.size() <<endl;
for (auto& dq : Ans) {
cout << dq.size() <<endl;
for (int v : dq) {
cout << v+1 << " ";
}
cout <<endl;
}
}
int main()
{
testcase();
return 0;
}
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 | // Online C++ Compiler - Build, Compile and Run your C++ programs online in your favorite browser #include<iostream> #include<vector> #include<queue> #include<algorithm> using namespace std; void testcase() { int n; cin >> n; vector <int> A(n), AS(n); for (int i = 0; i < n; i++) { cin >> A[i]; AS[i] = A[i]; } sort(AS.begin(), AS.end()); for (int i = 0; i < n; i++) { A[i] = lower_bound(AS.begin(), AS.end(), A[i]) - AS.begin(); } vector < deque <int> > Ans; vector <int> Last_it(n, -1); for (int it = 0; ; it++) { deque <int> Cur_row; for (int i = 0; i < n; i++) { int ai = A[i]; if (A[i] == i || Last_it[i] == it || Last_it[ai] == it) { continue; } Last_it[i] = it; Last_it[ai] = it; swap(A[i], A[ai]); Cur_row.push_front(i); Cur_row.push_back(ai); } if (!Cur_row.empty()) { Ans.push_back(Cur_row); } else { break; } } cout << Ans.size() <<endl; for (auto& dq : Ans) { cout << dq.size() <<endl; for (int v : dq) { cout << v+1 << " "; } cout <<endl; } } int main() { testcase(); return 0; } |
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