我怎样才能用 java 中的这个锯齿状数组制作这个例子

Question

How can i make this example with my codes? I approached the result but I could not reach

class Main { 
    public static void main(String[] args)   { 
        // Declare a 2-D array with 5 rows 
        int intArray[][] = new int[5][5]; 
          // create a jagged array that has i column(s) for ith row 
         for (int i=0; i<intArray.length; i++) 
           intArray[i] = new int[i+1]; 
          // Initialize the jagged array 
         int count = 1; 
         for (int i=0; i<intArray.length; i++) 
            for(int j=0; j<intArray[i].length; j++) 
               intArray[i][j] = count++; 

        // Display the values of 2D Jagged array 
       System.out.println("A two-dimensional Jagged Array contents:"); 
       for (int i=0; i<intArray.length; i++) 
        { 
           for (int j=0; j<intArray[i].length; j++) 
               System.out.print(intArray[i][j] + "  "); 
           System.out.println(); 
        } 
    } 
}

Answer 1

What you need is

• %2d which will print your number in 2 spaces

• to fill the remaining of blocks with 0 ( ie 5-intArray[i].length)

   for (int j=0; j<intArray[i].length; j++) System.out.printf("%2d ", intArray[i][j]); for (int j=intArray[i].length; j<5; j++) System.out.printf("%2d ", 0);

Output

 A two-dimensional Jagged Array contents: 1 0 0 0 0 2 3 0 0 0 4 5 6 0 0 7 8 9 10 0 11 12 13 14 15

Answer 2

You are not making a complete square 2D-array. Your array is like the following:

Because you are just making every row's size i+1 in your for loops. Delete those lines that initialize the array. Then you have a 2D array which is filled with 0 s. Now the rest of your code will work as you expect:

public static void main(String[] args)   { 
    // Declare a 2-D array with 5 rows 
    int intArray[][] = new int[5][5]; 

    // Initialize the jagged array 
    int count = 1; 
    for (int i=0; i<intArray.length; i++) 
       for(int j=0; j<i+1; j++) 
           intArray[i][j] = count++; 

    // Display the values of 2D Jagged array 
   System.out.println("A two-dimensional Jagged Array contents:"); 
   for (int i=0; i<intArray.length; i++) 
    { 
       for (int j=0; j<intArray[i].length; j++) 
           System.out.print(intArray[i][j] + "  "); 
       System.out.println(); 
    } 
}