Submission #990051

#	Time	Username	Problem	Language	Result	Execution time	Memory
990051		AdamGS	Sorting (IOI15_sorting)	C++17	100 / 100	127 ms	21244 KiB

sorting

#include "sorting.h"
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(a, b) for(int a = 0; a < (b); ++a)
#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
const int LIM=2e5+7;
int F[LIM];
int fnd(int x) {
  if(F[x]==x) return x;
  return F[x]=fnd(F[x]);
}
bool uni(int a, int b) {
  if(fnd(a)==fnd(b)) return false;
  F[fnd(b)]=fnd(a);
  return true;
}
int findSwapPairs(int n, int S[], int m, int X[], int Y[], int P[], int Q[]) {
  int po=0, ko=m;
  while(po<ko) {
    int sr=(po+ko)/2;
    vector<int>T(n);
    rep(i, n) T[i]=S[i];
    rep(i, sr) swap(T[X[i]], T[Y[i]]);
    rep(i, n) F[i]=i;
    int p=0;
    rep(i, n) if(uni(i, T[i])) ++p;
    if(p<=sr) ko=sr; else po=sr+1;
  }
  m=po;
  vector<int>T(n);
  rep(i, n) T[i]=S[i];
  vector<int>C=T;
  rep(i, m) swap(T[X[i]], T[Y[i]]);
  vector<int>Z(n);
  rep(i, n) Z[C[i]]=i;
  int l=0;
  rep(i, m) {
    swap(C[X[i]], C[Y[i]]);
    swap(Z[C[X[i]]], Z[C[Y[i]]]);
    while(l<n && T[l]==l) ++l;
    if(l==n) {
      P[i]=Q[i]=0;
      continue;
    }
    int a=Z[T[l]], b=Z[T[T[l]]];
    P[i]=a;
    Q[i]=b;
    swap(C[a], C[b]);
    swap(Z[C[a]], Z[C[b]]);
    swap(T[l], T[T[l]]);
  }
  return m;
}

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