Find errors: Array - wrong output

Question

I'm writing string[] to show multiple rows in the output. A stupid question, why the output is not 5 x 5?(I used i and j both from 0-4, then the ouput should be an array 5 x 5), can anyone help?

<ArrayOfstring xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
<string>0 30 3 13 25 30 </string>
<string>0 30 10 22 27 </string>
<string>0 30 12 17 </string>
<string>0 30 5 </string>
<string>0 30 </string>
</ArrayOfstring> 

Here's my input: .../3/10/12/5

Codes below:

    public IEnumerable<string> route5(int city1, int city2, int city3, int city4)
    {
        int[] city = new int[] { 0, city1, city2, city3, city4 };
        string[] layout = new string[5];
        
        for (int i = 0; i < 5; i++)
        {
            string message = "";
            for (int j = 0; j < 5; j++)
            {
                if (j - i == 0) message= "0"+" ";
                if (j > i)
                {
                    if (j - i == 1) message+= (city[j]).ToString()+" ";
                    else if (j - i == 2) message+= (city[j] + city[j - 1]).ToString()+" ";
                    else if (j - i == 3) message+= (city[j] + city[j - 1] + city[j - 2]).ToString() + " ";
                    else  message+= (city1 + city2 + city3 + city4).ToString() + " ";
                }
                else
                {
                    if (i - j == 1) message+= (city[i]).ToString()+" ";
                    else if (i - j == 2) message+= (city[i] + city[i - 1]).ToString() + " ";
                    else if (i - j == 3) message+= (city[i] + city[i - 1] + city[i - 2]).ToString()+ " ";
                    else message+= (city1 + city2 + city3 + city4).ToString() + " ";
                }

            }
            layout[i]= message;

        }
        return layout;
    }

Answer 1

As I stated in the comments, there are 2 problems:

1. In your line if (j - i == 0) message= "0"+" ";, the message= should be message+=. As it is in the question, that code overwrites the message string (which is what causes 0 to always be on the left side, rather than on the diagonal, and erases the initial i values in line i for i = 0, 1, 2, 3, 4), but you intended to append to the string instead.

2. The next line of if (j > i) should be else if (j > i) instead. As it's now, this causes one extra value being added (since instead of bypassing the j - i == 0 case, it's handled again in the else compound statement (i.e., within { and }) code below, resulting in message+= (city1 + city2 + city3 + city4).ToString() + " "; being executed since none of if (i - j == 1), if (i - j == 2) or if (i - j == 3) are true) rather than having just the intended 5 values.

You've confirmed these changes solve your problems with your comment of

it works!!! Thanks sooooo much.