Why is my C++ code triggering a stack overflow?
#include "stdafx.h"
#include <iostream>
using namespace std;
int _tmain(int argc, _TCHAR* argv[])
{
cout<<"Enter an odd number for the order of magic square: ";
cin>>num;
int sqr[5][5];
for (int i=0; i<num; i++)
for (int j=0;j<num; j++)
sqr [i][j]=0;
return 0;
}
int sqr[5][5];
You defined sqr as double dimension array which col and row are both 5. The valid col/row are between [0..4], You need to make sure num < 5 && num > 0
You'd better usevector<vector<int> >, whose size be dynamically increased,
or change your code to
for (int i=0; i<num &&i < 5; i++)
for (int j=0;j<num && j < 5; j++)
sqr [i][j]=0;
since your declaration of sqr is sqr[5][5].
may be there should exists: int num; or num may become a large number,resulting from a string. add: printf("%d",num); for test to see if it is larger than 4.
Did you want to create an n x n matrix based on input 'n'?
If so, you shouldn't statically allocate the matrix (see other answers for why). Assert if 'n' is not a number.
To create the matrix:
int **sqr = new int*[n];
for (int i = 0; i < n; i++)
sqr[i] = new int[n];
This creates your created a 2D matrix of order n x n. To index into it, you can use sqr[row][col] (Remember: x denotes columns, y denotes rows! And don't forget to delete all this memory!)
If you want to use STL, then you can use create a vector of vectors without doing all this C style pointer stuff!
numdeclared?