GETTING INPUT

SCENARIO 3A
GETTING n SPACE DELIMITED DATA PER LINE OVER m LINES (n & m are known before run-time)

If we want to process each line one at a time, then we can simply use the solution in scenario 4 and place that inside a loop. However, sometimes we need to store all data in order to process it. In this case, we will store our data in a 2D array.

SAMPLE INPUT (n = 5, m = 3)

5 3 0 2 1
2 4 5 1 0
9 3 1 5 8

Here is an example.

EXAMPLE 1

Below is an example where the program reads in 4 lines of 3 integers and places all the data into a 2D array. Note that instead of n, we use rows in the code. And instead of m, we use cols in the code.

import java.util.Arrays;

import java.util.Scanner;

public class InputBasics

{

public static void main(String[] args)

{

Scanner scr = new Scanner(System.in);

int rows = 4; //n

int cols = 3; //m

int[][] grid = new int[rows][cols];

for (int r=0; r<rows; r++)

{

for (int c=0; c<cols; c++)

{

grid[r][c] = scr.nextInt();

}

}

//process the data array here

System.out.println(Arrays.deepToString(grid));

}

}

SAMPLE EXECUTION

1 2 3

4 5 6

7 8 9

3 4 5

[[1, 2, 3], [4, 5, 6], [7, 8, 9], [3, 4, 5]]

Here is another example with strings.

EXAMPLE 2

Below is an example where the program reads in 3 lines of 2 Strings and places all the data into a 2D array. Notice it is very similar to the above example.

import java.util.Arrays;

import java.util.Scanner;

public class InputBasics

{

public static void main(String[] args)

{

Scanner scr = new Scanner(System.in);

int rows = 3; //n

int cols = 2; //m

String[][] grid = new String[rows][cols];

for (int r=0; r<rows; r++)

{

for (int c=0; c<cols; c++)

{

grid[r][c] = scr.next();

}

}

//process the data array here

System.out.println(Arrays.deepToString(grid));

}

}

SAMPLE EXECUTION

cat bat

mat sat

rat nat

[[cat, bat], [mat, sat], [rat, nat]]