Submission #23494

#	Time	Username	Problem	Language	Result	Execution time	Memory
23494		ruhanhabib39	Sorting (IOI15_sorting)	C++14	36 / 100	4 ms	640 KiB

sorting

#include "sorting.h"
#include <algorithm>
#include <cstring>

const int MAXN = 2e5;

int N, M, *S, *X, *Y, *P, *Q;

int fp[MAXN + 10];
int carry[MAXN + 10];
int wfp[MAXN + 10];
int platei[MAXN + 10];
int plateid[MAXN + 10];

void swap_plate(int x, int y) {
   int xp = plateid[x], yp = plateid[y];
   std::swap(platei[xp], platei[yp]);
   std::swap(plateid[x], plateid[y]);
}

bool oka(int R) {
   std::fill(P, P + M, 0); std::fill(Q, Q + M, 0);
   for(int i = 0; i < N; i++) {
      platei[i] = plateid[i] = fp[i] = i;
      carry[i] = S[i];
   }
   for(int i = 0; i < R; i++) {
      int x = X[i], y = Y[i];
      swap_plate(x, y);
   }
   for(int i = 0; i < N; i++) {
      fp[i] = platei[i];
      wfp[fp[i]] = i;
   }
   for(int i = 0; i < N; i++) {
      platei[i] = i;
   }
   int x = 0;
   for(int i = 0; i < R; i++) {
      swap_plate(X[i], Y[i]);
      while(x < N && fp[x] == carry[x]) {
         x++;
      }
      if(x == N) break;
      int y = wfp[carry[x]];
      P[i] = platei[x]; Q[i] = platei[y];
      std::swap(carry[x], carry[y]);
   }
   while(x < N && fp[x] == carry[x]) {
      x++;
   }
   return x == N;
}

int findSwapPairs(int N_, int S_[], int M_, int X_[], int Y_[], int P_[], int Q_[]) {
   N = N_; M = M_; S = S_; X = X_; Y = Y_; P = P_; Q = Q_;
   int lo = 0, hi = M;
   while(lo < hi) {
      int m = (lo + hi) / 2;
      if(oka(m)) hi = m;
      else lo = m + 1;
   }
   oka(lo);
   return lo;
}

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