Submission #1248211

#	Time	Username	Problem	Language	Result	Execution time	Memory
1248211		kl0989e	정렬하기 (IOI15_sorting)	C++20	100 / 100	210 ms	43672 KiB

sorting

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

#define ll long long
#define pi pair<int, int>
#define pl pair<ll, ll>
#define vi vector<int>
#define vl vector<ll>
#define fi first
#define se second
#define pb push_back
#define all(x) (x).begin(),(x).end()

bool check(int n, int s[], int r, int x[], int y[], int p[], int q[]) {
	for (int i=0; i<r; i++) {
		swap(s[x[i]],s[y[i]]);
		swap(s[p[i]],s[q[i]]);
	}
	bool ok=1;
	for (int i=0; i<n; i++) {
		ok&=(s[i]==i);
	}
	return ok;
}

int solve(int n, int s[], int m, int x[], int y[], int p[], int q[]) {
	if (n==1) {
		return 0;
	}
	int ss[n];
	for (int i=0; i<n; i++) {
		ss[i]=s[i];
	}
	vi goesto(n);
	iota(all(goesto),0);
	for (int i=m-1; i>=0; i--) {
		swap(goesto[x[i]],goesto[y[i]]);
	}
	vi to(n);
	vi getpos(n);
	for (int i=0; i<n; i++) {
		to[goesto[i]]=i;
		getpos[s[i]]=i;
	}
	int ind=0;
	for (int i=0; i<n && ind<m; i++) {
		swap(s[x[ind]],s[y[ind]]);
		swap(getpos[s[x[ind]]],getpos[s[y[ind]]]);
		swap(goesto[x[ind]],goesto[y[ind]]);
		swap(to[goesto[x[ind]]],to[goesto[y[ind]]]);
		if (s[to[i]]==i) {
			swap(s[x[ind]],s[y[ind]]);
			swap(getpos[s[x[ind]]],getpos[s[y[ind]]]);
			swap(goesto[x[ind]],goesto[y[ind]]);
			swap(to[goesto[x[ind]]],to[goesto[y[ind]]]);
			continue;
		}
		p[ind]=to[i];
		q[ind]=getpos[i];
		swap(s[p[ind]],s[q[ind]]);
		swap(getpos[s[p[ind]]],getpos[s[q[ind]]]);
		ind++;
		if (ind>m) {
			return -1;
		}
	}
	for (int i=ind; i<m; i++) {
		p[i]=0;
		q[i]=0;
	}
	if (!check(n,ss,m,x,y,p,q)) {
		return -1;
	}
	return m;
}

int findSwapPairs(int n, int s[], int m, int x[], int y[], int p[], int q[]) {
	int ans=1e9;
	int l=0,r=m;
	while (l<=r) {
		int mm=l+(r-l)/2;
		int ss[n];
		for (int i=0; i<n; i++) {
			ss[i]=s[i];
		}
		int *pp=(int*)malloc(sizeof(int)*(unsigned int)mm), *qq=(int*)malloc(sizeof(int)*(unsigned int)mm);
		int t=solve(n,ss,mm,x,y,pp,qq);
		if (t==-1) {
			l=mm+1;
		}
		else {
			for (int i=0; i<t; i++) {
				p[i]=pp[i];
				q[i]=qq[i];
			}
			ans=t;
			r=t-1;
		}
	}
	assert(check(n,s,ans,x,y,p,q));
	return ans;
}

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