제출 #542824

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
542824		zggf	고대 책들 (IOI17_books)	C++14	0 / 100	1 ms	308 KiB

books

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

using namespace std;

vector<int> parent, ranga;

int find(int x){
	if(parent[x]==-1) return x;
	parent[x] = find(parent[x]);
	return parent[x];
}

void join(int a, int b){
	a = find(a);
	b = find(b);
	if(a==b) return;
	if(ranga[a]>ranga[b]){
		parent[b] = a;
	}else if(ranga[b]>ranga[a]){
		parent[a] = b;
	}else{
		parent[b] = a;
		ranga[a]++;
	}
}

long long minimum_walk(std::vector<int> p, int s) {
	int n = p.size();
	vector<int> odw(n);
	parent.resize(n, -1);
	ranga.resize(n);
	long long wyn = 0;
	queue<int> q;
	vector<int> cost(n, 1e9);
	for(int i = 0; i < n; i++){
		int pt = i;
		if(!odw[pt]){
			if(p[pt]!=pt){
				while(!odw[pt]){
					odw[pt] = true;
					cost[pt] = 0;
					q.push(pt);
					wyn+=abs(p[pt]-pt);
					join(pt, p[pt]);
					pt = p[pt];	
				}
			}else{
			       	odw[pt] = true;
				if(pt==s)
					cost[s] = 0, q.push(s);
			}
		}
	}
	while(q.size()){
		int x = q.front();
		//cout<<x<<" "<<cost[x]<<'\n';
		q.pop();
		if(x>0) if(find(x-1)!=find(x))
				if(cost[x-1]==1e9){
					cost[x-1] = cost[x]+1;
					q.push(x-1);
					join(x-1, x);
				}else{
					wyn+=2*(cost[x-1]+cost[x]+1);
					join(x-1, x);
				}
		if(x<n-1) if(find(x+1)!=find(x))
				if(cost[x+1]==1e9){
					cost[x+1] = cost[x]+1;
					q.push(x+1);
					join(x+1, x);
				}else{
					wyn+=2*(cost[x+1]+cost[x]+1);
					join(x+1, x);
				}
	}
	return wyn;
}

컴파일 시 표준 에러 (stderr) 메시지

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:59:13: warning: suggest explicit braces to avoid ambiguous 'else' [-Wdangling-else]
   59 |   if(x>0) if(find(x-1)!=find(x))
      |             ^
books.cpp:68:15: warning: suggest explicit braces to avoid ambiguous 'else' [-Wdangling-else]
   68 |   if(x<n-1) if(find(x+1)!=find(x))
      |               ^

• Subtask 1: 0 / 12
• Subtask 2: 0 / 10
• Subtask 3: 0 / 28
• Subtask 4: 0 / 20
• Subtask 5: 0 / 30