Submission #1223169

#	Time	Username	Problem	Language	Result	Execution time	Memory
1223169		fermat	Sorting (IOI15_sorting)	C++20	100 / 100	113 ms	13076 KiB

sorting

#include "sorting.h"
#include <bits/stdc++.h>

#define fr first
#define sc second
#define pb push_back
#define mk make_pair
#define all(s) s.begin(), s.end()

using namespace std;

const int N = 2e5 + 5;

int sz, cnt, res, u[N], a[N], pos[N], asd[N];

void dfs (int v) {
 cnt++;
 u[v] = 1;
 if (u[ a[v] ] == 0)
  dfs(a[v]);
}

int findSwapPairs(int n, int b[], int m, int x[], int y[], int p[], int q[]) {
    bool fl = 1;
    for (int i = 0; i < n; i++) {
  a[i] = b[i];
  if (a[i] != i)
   fl = 0;
 }
 if (fl)
  return 0;
 
 int l = 0, r = m;
 while (r - l > 1) {
  int md = (l + r) >> 1;
  
  for (int i = 0; i < n; i++)
   a[i] = b[i];
   
  for (int i = 0; i < md; i++) {
   swap( a[ x[i] ], a[ y[i] ] );
  }
  res = 0;
  memset(u, 0, sizeof(u));
  for (int j = 0; j < n; j++) {
   if (u[j]) continue;
   cnt = 0; dfs(j);
   res += cnt - 1;
  }
  if (res <= md)
   r = md;
  else
   l = md;
  
 }
 for (int i = 0; i < n; i++)
  a[i] = b[i];
  
 for (int i = 0; i < r; i++) {
  swap( a[ x[i] ], a[ y[i] ] );
 }
 for (int j = 0; j < n; j++)
  pos[b[j]] = j, asd[a[j]] = j;
 
 int k = 0;
 
 for (int j = 0; j < n; j++) {
  if (a[j] == j) continue;
  pos[ b[x[k]] ] = y[k];
  pos[ b[y[k]] ] = x[k];
  swap( b[x[k]], b[y[k]] );
  p[k] = pos[a[j]], q[k] = pos[j];
  swap( b[pos[ a[j] ]], b[pos[j]] );
  swap( pos[ a[j] ], pos[j] );
  swap(a[j], a[asd[j]]);
  asd[a[asd[j]]] = asd[j];
  k++;
 }
 return r;
}

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