Submission #1018543

#	Time	Username	Problem	Language	Result	Execution time	Memory
1018543		huutuan	Sorting (IOI15_sorting)	C++14	54 / 100	15 ms	856 KiB

sorting

#include "sorting.h"

#include <bits/stdc++.h>

using namespace std;

int a[200010], pos[200010];

int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
   iota(a, a+N, 0);
   for (int i=0; i<N; ++i) pos[S[i]]=i;
   for (int i=M-1; i>=0; --i) swap(a[X[i]], a[Y[i]]);
   if (is_sorted(S, S+N)) return 0;
   for (int i=0; i<M; ++i){
      P[i]=Q[i]=0;
      swap(a[X[i]], a[Y[i]]);
      if (is_sorted(S, S+N)) return i+1;
      swap(S[X[i]], S[Y[i]]);
      pos[S[X[i]]]=X[i];
      pos[S[Y[i]]]=Y[i];
      for (int j=0; j<N; ++j) if (a[j]!=S[j]){
         int k=pos[a[j]];
         if (S[j]==a[k]){
            P[i]=j, Q[i]=k;
            break;
         }
      }
      if (!P[i] && !Q[i]){
         for (int j=0; j<N; ++j) if (a[j]!=S[j]){
            int k=pos[a[j]];
            P[i]=j, Q[i]=k;
            break;
         }
      }
      swap(S[P[i]], S[Q[i]]);
      pos[S[P[i]]]=P[i];
      pos[S[Q[i]]]=Q[i];
      if (is_sorted(S, S+N)) return i+1;
   }
   for (int j=0; j<N; ++j) assert(S[j]==j);
   return M;
}

• Subtask 1: 8 / 8
• Subtask 2: 12 / 12
• Subtask 3: 16 / 16
• Subtask 4: 18 / 18
• Subtask 5: 0 / 20
• Subtask 6: 0 / 26