[BOJ/JAVA] 백준 1956번 : 운동

1956번: 운동

 

 

 

 

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• 풀이

 

플로이드-와샬 알고리즘 사용

 

 

• 코드

 

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.PriorityQueue;

public class Main {
	static int V, E, answer;
	static int[][] array;
	

	public static void main(String[] args) throws Exception {
		SetData();
		System.out.println(answer);
	}

	// 데이터
	private static void SetData() throws Exception {
		InputReader in = new InputReader(System.in);
		
		V = in.nextInt();
		E = in.nextInt();
		answer = 50000;
		array = new int[V+1][V+1];
		
		for(int i = 1; i <= V; i++){
			Arrays.fill(array[i], 50000);
		}
		
		for(int i = 0 ; i < E; i++) {
			array[in.nextInt()][in.nextInt()] = in.nextInt();
		}
		
		for (int k = 1; k <= V; k++) {
			for (int i = 1; i <= V; i++) {
				for (int j = 1; j <= V; j++) {
					array[i][j] = Math.min(array[i][k] + array[k][j], array[i][j]);
				}
			}
		}
		
		for(int i = 1; i<=V; i++){
			answer = Math.min(array[i][i], answer);
		}
		
		if(answer == 50000) answer = -1;
	}
}

class InputReader {
	private final InputStream stream;
	private final byte[] buf = new byte[8192];
	private int curChar, snumChars;

	public InputReader(InputStream st) {
		this.stream = st;
	}

	public int read() {
		if (snumChars == -1)
			throw new InputMismatchException();
		if (curChar >= snumChars) {
			curChar = 0;
			try {
				snumChars = stream.read(buf);
			} catch (IOException e) {
				throw new InputMismatchException();
			}
			if (snumChars <= 0)
				return -1;
		}
		return buf[curChar++];
	}

	public int nextInt() {
		int c = read();
		while (isSpaceChar(c)) {
			c = read();
		}
		int sgn = 1;
		if (c == '-') {
			sgn = -1;
			c = read();
		}
		int res = 0;
		do {
			res *= 10;
			res += c - '0';
			c = read();
		} while (!isSpaceChar(c));
		return res * sgn;
	}

	public long nextLong() {
		int c = read();
		while (isSpaceChar(c)) {
			c = read();
		}
		int sgn = 1;
		if (c == '-') {
			sgn = -1;
			c = read();
		}
		long res = 0;
		do {
			res *= 10;
			res += c - '0';
			c = read();
		} while (!isSpaceChar(c));
		return res * sgn;
	}

	public int[] nextIntArray(int n) {
		int a[] = new int[n];
		for (int i = 0; i < n; i++) {
			a[i] = nextInt();
		}
		return a;
	}

	public String nextLine() {
		int c = read();
		while (isSpaceChar(c))
			c = read();
		StringBuilder res = new StringBuilder();
		do {
			res.appendCodePoint(c);
			c = read();
		} while (!isEndOfLine(c));
		return res.toString();
	}

	public boolean isSpaceChar(int c) {
		return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
	}

	private boolean isEndOfLine(int c) {
		return c == '\n' || c == '\r' || c == -1;
	}
}