图论算法 最短路 Floyd

package com.bluecup.org;

import java.util.Arrays;
import java.util.Scanner;

public class ShortestPathFloyd {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub

		Scanner scan = new Scanner(System.in);
		int n = scan.nextInt(), value;
		int d[][] = new int[n + 1][n + 1];
		for (int i = 1; i <= n; i++)
			Arrays.fill(d[i], 255);
		do {
			int i = scan.nextInt();
			int j = scan.nextInt();
			value = scan.nextInt();
			if (value > 0)
				d[i][j] = value;
		} while (value > 0);
		for (int i = 1; i <= n; i++) {
			for (int j = 1; j <= n; j++)
				for (int k = 1; k <= n; k++) {
					if (i != j && i != k && j != k)
						if (d[j][k] > d[j][i] + d[i][k])
							d[j][k] = d[j][i] + d[i][k];
				}
		}
		System.out.println(d[1][n]);
	}

}