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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3.  
  4. int main() {
  5.     ios::sync_with_stdio(false);
  6.     cin.tie(nullptr);
  7.     int N; 
  8.     if(!(cin >> N)) return 0;
  9.     vector<int> P(N+1), pos(N+1);
  10.     for (int i=1;i<=N;i++){ cin >> P[i]; pos[P[i]]=i; }
  11.     vector<pair<int,int>> ops;
  12.     for (int i=1;i<=N;i++){
  13.         int p = pos[i];
  14.         if (p==i) continue;
  15.         ops.emplace_back(i,p);
  16.         reverse(P.begin()+i, P.begin()+p+1);
  17.         for (int k=i;k<=p;k++) pos[P[k]]=k;
  18.     }
  19.     cout << (int)ops.size() << '\n';
  20.     for (auto &op: ops) cout << op.first << ' ' << op.second << '\n';
  21.     return 0;
  22. }
Success #stdin #stdout 0.01s 5304KB
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6
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https://ideone.com/lJw3mv
language:
C++ (gcc 8.3)
created:
17 days ago
visibility:
public

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