#include "sorting.h" #include <bits/stdc++.h> using namespace std; #define fi first #define se second #define REP(i, n) for (int i = 0, _n = (n); i < _n; ++i) int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) { auto check = [&] (int r, bool trace = false) { vector <int> perm(S, S + N); REP(i, r) swap(perm[X[i]], perm[Y[i]]); vector <int> pos(N); REP(i, N) pos[perm[i]] = i; vector <pair <int, int>> swaps; auto __swap = [&] (int i, int j) { swap(perm[i], perm[j]); swap(pos[perm[i]], pos[perm[j]]); }; REP(i, N) { if (perm[i] != i) { swaps.push_back(make_pair(perm[i], i)); __swap(i, pos[i]); } } if (!trace) return swaps.size() <= r; while (swaps.size() < r) swaps.push_back(make_pair(0, 0)); copy(S, S + N, perm.begin()); REP(i, N) pos[perm[i]] = i; REP(i, r) { __swap(X[i], Y[i]); P[i] = pos[swaps[i].fi]; Q[i] = pos[swaps[i].se]; __swap(P[i], Q[i]); } return true; }; int l = 0, r = N; while (l < r) { int m = l + r >> 1; if (check(m)) r = m; else l = m + 1; } check(l, true); return l; }

sorting.cpp: In lambda function:
sorting.cpp:27:38: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   27 |      if (!trace) return swaps.size() <= r;
      |                         ~~~~~~~~~~~~~^~~~
sorting.cpp:28:26: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   28 |      while (swaps.size() < r) swaps.push_back(make_pair(0, 0));
      |             ~~~~~~~~~~~~~^~~
sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:41:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   41 |      int m = l + r >> 1;
      |              ~~^~~
sorting.cpp:10:39: warning: unused parameter 'M' [-Wunused-parameter]
   10 | int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
      |                                   ~~~~^