Java Shortest Path general solution

Question

The 'p' is the number of nodes. So now in my solution the user has to type in all the matrix elements, in case of 7 nodes, 49 numbers. I don't want it this way. I would like to ask the user the distances from one point to the other. Sorry for the weird names in my program, they're in my language. latogatott = visited, tav=distance

package legrovidebb_ut;

import java.util.Scanner;

public class Legrovidebb_ut {

public static void main (String[] args) {

    Scanner scan = new Scanner(System.in);

       System.out.println("Adja meg a pontok szamat: ");

    int p;

    p = scan.nextInt( );

    int[][] matrix = new int [p][p];
    int[] tav = new int[p];
    int[] latogatott = new int[p];
    int[] pre = new int[p];
    int min;
    int nextNode = 0;


    System.out.println("Enter the matrix!");


    for (int i=0; i<p; i++){

        latogatott[i]=0;

        pre[i]=0;

        for (int j=0;j<p;j++){

            matrix[i][j] = scan.nextInt();
            if(matrix[i][j]== 0)
                matrix[i][j]=999;
        }
    }
    tav = matrix[0];
    tav[0]=0;
    latogatott[0]=1;

    for (int i=0;i<p;i++){
        min=999;

    for(int j=0;j<p;j++){
        if(min>tav[j] && latogatott[j]!=1){

            min=tav[j];
            nextNode=j;
        }
    }
    latogatott[nextNode]=1;

    for(int c=0;c<p;c++){
        if(latogatott[c]!=1){
            if(min+matrix[nextNode][c]<tav[c]){
                tav[c]=min+matrix[nextNode][c];
                pre[c]=nextNode;
            }
        }
    }
    }
    for (int i=0;i<p;i++){
        System.out.print("|" + tav[i]);
    }
    System.out.println("|");

    for(int i=0;i<p;i++){
        int j;
        System.out.print("Ut: " + (i+1));
        j=i;

        do{
            j=pre[j];
            System.out.println(" <- " + (j+1));
        }while(j!=0);
        System.out.println();
    }
}

}

Answer 1

If your graph is undirected and you want the user to input the distances between each two nodes (as stated in your comment), you will need a loop through all your nodes and another loop through all the other nodes, as a distance for 2-1 is not needed if you have a distance for 1-2:

for(int i = 0; i < p; i++) {
  for(int k = i+1; k < p; k++) {
    // ask user for distance between i and k
  }
}