Q: Error: Exception in thread "main" java.util.InputMismatchException

I am writing a program to solve the all-pairs shortest paths problem using the Floyd-Warshall algorithm. I am given a test file in txt format in which the first int is the number of vertices, the second int is the value of infinity and the rest is a matrix containing length information. This is my test file and the Java code I wrote.

3
999
0  16 999
3  0  18
12 1  0

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;


public class FloydWarshall
{
    private int adj[][];
    private int N;

    public FloydWarshall(int N)
    {
        adj = new int[N][N];
        this.N = N;
    }

    public void floydwarshall(int adj[][])
    {
        // i = source vertex
        // j = destination vertex
        // k = intermediate vertex
        int dist[][] = new int[N][N];

        // Initial values of shortest distances based on shortest paths
        // considering no intermediate vertex.
        for (int i = 0; i < N; i++)
        {
            for (int j = 0; j < N; j++)
            {
                dist[i][j] = adj[i][j];
            }
        }

        // If vertex k is on the shortest path from i to j, update the value of dist[i][j]
        for (int k = 0; k < N; k++)
        {
            for (int i = 0; i < N; i++)
            {
                for (int j = 0; j < N; j++)
                {
                    if (dist[i][k] + dist[k][j] < dist[i][j])
                        dist[i][j] = dist[i][k] + dist[k][j];
                }
            }
        }

        // Print the result
        for (int i = 0; i < N; i++)
        {
            for (int j = 0; j < N; j++)
            {
                System.out.print(dist[i][j] + "\t");
            }
            System.out.println();
        }
    }

    public static void main(String args[])
            throws FileNotFoundException {

        int adj[][]; // Adjacency matrix
        int N; // Number of vertices
        final int INFINITY; // Define infinity value

        File testFile = new File("src/test.txt"); // Enter file pathname
        Scanner inFile = new Scanner(testFile);

        // Read first int on first line as the number of vertices
        N = inFile.nextInt();
        // Read first int on second line as the infinite value
        INFINITY = inFile.nextInt();

        // System.out.println(N);
        // System.out.println(INFINITY);

        // An adjacency matrix to store input from the rest of the file
        adj = new int[N][N];

        // Input the matrix
        for (int i = 0; i < N; i++) {
            for (int j = 0; j < N; j++) {
                adj[i][j] = inFile.nextInt();
            }
        }

        // Print Solution
        System.out.println("The matrix of shortest path distances is:");
        FloydWarshall f = new FloydWarshall(N);
        f.floydwarshall(adj);
        inFile.close();
    }
}

I constantly get this error when I tried to input the data from txt file. My code works fine if I just manually input all the data via keyboard.

Exception in thread "main" java.util.InputMismatchException at java.base/java.util.Scanner.throwFor(Scanner.java:939) at java.base/java.util.Scanner.next(Scanner.java:1594) at java.base/java.util.Scanner.nextInt(Scanner.java:2258) at java.base/java.util.Scanner.nextInt(Scanner.java:2212) at FloydWarshall.main(FloydWarshall.java:81)

I had the same type of error for my last project, so I am so confused about how to input data from txt file.

I deleted the extra spaces in my test file and the code finally worked.

3
999
0 16 999
3 0 18
12 1 0