Member Avatar for FraidaL

This code is supposed to output a hollow square (size and symbols to be determined by the user), but it doesn't do that. First of all, if I set the size of the square to be 5, it outputs 10-5 sets of both symbols. Also the right column is in the middle of the square, not at the end. So right now my square of size 5 looks like this:

* + * + * + * + * + 
* +    * + 
* +    * + 
* +    * + 
* + * + * + * + * +

I need it to look like this:

*  +  *  +  *
+           +
*           *
+           +
*  +  *  +  *

Here is the code I have so far:

#include<iostream>
using namespace std;

int main()
{
    cout << "Please enter a size for the square: ";
    int size;
    cin >> size;
    cout << "Please enter first symbol: ";
    char sym1;
    cin >> sym1;
    cout << "Please enter a second symbol: ";
    char sym2;
    cin >> sym2;

    for (int row=1; row<=size; row++)
    {
        for (int col=1; col<=size; col++)
        {
            if (row>1 && row<size && col>1 && col<size)
                cout << " ";
            else
                cout << sym1 << " " << sym2 << " ";
        }
        cout << "\n";
    }

    return 0;
}

What am I doing wrong?

  • 3 Contributors
  • 3 Replies
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  • 2 Hours Discussion Span
  • Latest Post Latest Post by FraidaL

Dani AI

Generated

Quick diagnosis: the loop prints both symbols for every border cell, so each "cell" becomes several characters wide and the right column appears shifted. Also the interior branch prints fewer characters than a border cell, so columns don't line up. Instead of printing both symbols per iteration, print exactly one symbol per cell and keep a fixed cell width (symbol + a trailing space). Choose which symbol to print by parity of row+column so the alternation is consistent both across and down the grid.

A simple, robust approach (0-based loops) — print a border cell when r==0 || r==n-1 || c==0 || c==n-1, and use ((r + c) % 2 == 0) to pick sym1 or sym2. For interior cells print the same number of spaces as a border cell occupies (here two characters: symbol + space) so alignment stays intact.

#include <iostream>
using namespace std;

int main() {
    int n; char s1, s2;
    cout << "Please enter a size for the square: "; if (!(cin >> n)) return 0;
    cout << "Please enter first symbol: "; cin >> s1;
    cout << "Please enter a second symbol: "; cin >> s2;

    for (int r = 0; r < n; ++r) {
        for (int c = 0; c < n; ++c) {
            bool border = (r == 0 || r == n-1 || c == 0 || c == n-1);
            if (border) cout << ((r + c) % 2 == 0 ? s1 : s2) << ' ';
            else       cout << "  ";
        }
        cout << '\n';
    }
    return 0;
}

Notes and troubleshooting: for n <= 2 the square is all border, so no hollow interior. If you want wider spacing, print more spaces for both border and interior (or use setw from <iomanip>). This parity method handles even/odd sizes without extra toggles; it also implements the same idea suggested for alternation while applying it only to the border, and it avoids the offset concerns mentioned by . — this keeps the middle hollow and aligns the right edge.

Recommended Answers

All 3 Replies

Member Avatar for histrungalot

Check out this vs. what you have.

$ ./a.out
Please enter a size for the square: 5
Please enter first symbol: +
Please enter a second symbol: *
* + * + * 
+ * + * + 
* + * + * 
+ * + * + 
* + * + *

Keep in mind that if odd the columns will alternate and if even it wont alternate down

$ ./a.out
Please enter a size for the square: 6
Please enter first symbol: +
Please enter a second symbol: *
* + * + * + 
* + * + * + 
* + * + * + 
* + * + * + 
* + * + * + 
* + * + * +
Code
#include<iostream>
using namespace std;

int main()
{
    cout << "Please enter a size for the square: ";
    int size;
    cin >> size;
    cout << "Please enter first symbol: ";
    char sym1;
    cin >> sym1;
    cout << "Please enter a second symbol: ";
    char sym2;
    cin >> sym2;

    int other(0); 
    for (int row=1; row<=size; row++) {
        for ( int col(1); col<=size; col++){
           // This makes it go every other
           if ( other++%2 ){
              cout << sym1 << " ";
           } else{
              cout << sym2 << " ";
           }
        }
        cout << endl;
     }
     cout << "\n";

    return 0;
}
Edited by histrungalot because: Format, spelling
Member Avatar for scudzilla

Also, to alternate the symbols (going down) if the size is even, just add 1 to other before the for loop.

Edited by scudzilla
Member Avatar for FraidaL

Thanx for the help, but I needed the middle to be empty. I figured out a different way to do it in the end.

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