Submission #1247814

#	Time	Username	Problem	Language	Result	Execution time	Memory
1247814		kl0989e	정렬하기 (IOI15_sorting)	C++20	54 / 100	14 ms	2100 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;
}

bool sorted(int n, int s[]) {
	bool ok=1;
	for (int i=0; i<n && ok; 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];
	}
	vector<vi> lst(n,{m});
	for (int i=m-1; i>=0; i--) {
		if (x[i]!=y[i]) {
			lst[x[i]].pb(i);
			lst[y[i]].pb(i);
		}
	}
	priority_queue<pi> qu;
	vi loc(n);
	int corr=0;
	for (int i=0; i<n; i++) {
		loc[s[i]]=i;
		if (s[i]==i) {
			corr++;
			continue;
		}
		qu.push({lst[i].back(),i});
	}
	int ind=0;
	while (corr<n && ind<m) {
		if (x[ind]!=y[ind] && lst[x[ind]].size()>0 && lst[x[ind]].back()==ind) {
			lst[x[ind]].pop_back();
			lst[y[ind]].pop_back();
			if (s[y[ind]]!=x[ind]) {
				qu.push({lst[x[ind]].back(),x[ind]});
			}
			if (s[x[ind]]!=y[ind]) {
				qu.push({lst[y[ind]].back(),y[ind]});
			}
		}
		if (s[x[ind]]==x[ind]) {
			corr--;
		}
		if (s[y[ind]]==y[ind]) {
			corr--;
		}
		if (s[x[ind]]==y[ind]) {
			corr++;
		}
		if (s[y[ind]]==x[ind]) {
			corr++;
		}
		swap(loc[s[x[ind]]],loc[s[y[ind]]]);
		swap(s[x[ind]],s[y[ind]]);
		if (corr==n) {
			p[ind]=0;
			q[ind]=0;
			ind++;
			break;
		}
		auto [time,i]=qu.top();
		qu.pop();
		if (s[i]==i || time!=lst[i].back()) {
			if (s[x[ind]]==x[ind]) {
				corr--;
			}
			if (s[y[ind]]==y[ind]) {
				corr--;
			}
			if (s[x[ind]]==y[ind]) {
				corr++;
			}
			if (s[y[ind]]==x[ind]) {
				corr++;
			}
			swap(loc[s[x[ind]]],loc[s[y[ind]]]);
			swap(s[x[ind]],s[y[ind]]);
			continue;
		}
		p[ind]=i;
		q[ind]=loc[i];
		if (s[p[ind]]==p[ind]) {
			corr--;
		}
		if (s[q[ind]]==q[ind]) {
			corr--;
		}
		if (s[p[ind]]==q[ind]) {
			corr++;
		}
		if (s[q[ind]]==p[ind]) {
			corr++;
		}
		swap(loc[s[p[ind]]],loc[s[q[ind]]]);
		swap(s[p[ind]],s[q[ind]]);
		ind++;
	}
	if (!check(n,ss,ind,x,y,p,q)) {
		return -1;
	}
	return ind;
}

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)m), *qq=(int*)malloc(sizeof(int)*(unsigned int)m);
		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: 0 / 20
• Subtask 6: 0 / 26