Question

For some reason my program is crashing in the loop, and im unsure what is causing the problem

Here is my code.

#include<iostream>
#include<string>
#include<fstream>
using namespace std;



int main()
{
    ifstream fin;
    ofstream fout;

    fin.open("dice.in");
    fout.open("dice.out");

    string line;
    int boardsize;
    int top;
    int side;

    fin >> boardsize >> top >> side;
    while(boardsize != 0)
    {
        int ** board;
        board = new int*[boardsize];

        //creates  a multi dimensional dynamic array
        for(int i = 0; i < boardsize; i++)
        {
            board[i] = new int[boardsize];
        }

        //loop through the 2d array
        for(int i = 0; i <= boardsize; i++)
        {
            getline(fin, line);
            for(int j = 0; j < boardsize; j++)
            {
                if(i != 0)
                board[i][j] = (int)line[j];
            }
            line.clear();
        }


        fin >> boardsize >> top >> side;
    }

    fin.close();
    fout.close();
}

Here is the input file i am using

3 6 4
632
562
463
3 6 4
632
556
423
7 6 4
4156*64
624*112
23632**
4555621
6*42313
4231*4*
6154562
0 0 0

Answer 1

    //loop through the 2d array
    for(int i = 0; i <= boardsize; i++)
    {
        getline(fin, line);
        for(int j = 0; j < boardsize; j++)
        {
            if(i != 0)
            board[i][j] = (int)line[j];
        }
        line.clear();
    }

needs to be

    //loop through the 2d array
    for(int i = 0; i < boardsize; i++)         // note < instead of <=
    {
        getline(fin, line);
        for(int j = 0; j < boardsize; j++)
        {                                      // not I deleted if statement
            board[i][j] = (int)line[j];
        }
        line.clear();
    }

This is because arrays in C++ start at the index 0, so when you allocate an array of size three, as you do above with board = new int*[boardsize];, the indices of this array will be 0, 1, 2, ... boardsize-1, whereas your algorithm was using 1, 2, 3, ... boardsize which will be an out of bounds access because you only have n blocks allocated and you are trying to access (modify, actually) block n + 1, which will result in a segmentation fault.