Submission #1287373

#	Time	Username	Problem	Language	Result	Execution time	Memory
1287373		WH8	Sorting (IOI15_sorting)	C++20	0 / 100	1 ms	344 KiB

sorting

#include "sorting.h"
#include <bits/stdc++.h>
using namespace std;

int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
    int l=-1,r=M;
    for(int i=0;i<M;i++)P[i]=Q[i]=0;
    while(l<r-1){
		int mid=(l+r)/2;
		vector<bool> vis(N, 0);
		vector<int> cur(N); 
		for(int i=0;i<N;i++)cur[i]=S[i];
		for(int i=0;i<mid;i++){
			swap(cur[X[i]], cur[Y[i]]);
		}
		int cycles=0;
		for(int i=0;i<N;i++){
			if(!vis[i]){
				cycles++;
				int c=i;
				vis[i]=true;
				while(cur[c]!=i){
					c=cur[c];
					vis[c]=true;
				}
			}
		}
		if(N-cycles <= mid){
			r=mid;
		}
		else l=mid;
	}
	vector<bool> vis(N, 0);
	vector<int> cur(N); 
	for(int i=0;i<N;i++)cur[i]=S[i];
	for(int i=0;i<r;i++){
		swap(cur[X[i]], cur[Y[i]]);
	}
	int cnt=0;
	for(int i=0;i<N;i++){
		if(!vis[i]){
			int c=i;
			vis[i]=true;
			while(cur[c]!=i){
				vis[c]=true;
				P[cnt]=c;
				Q[cnt]=cur[c];
				cnt++;				
				c=cur[c];
			}
		}
	}
	return r;
}

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