c - Seg Fault when initializing array -

i'm taking class on c, , running segmentation fault. understand, seg faults supposed occur when you're accessing memory hasn't been allocated, or otherwise outside bounds. 'course i'm trying initialize array (though rather large @ that)

am misunderstanding how parse 2d array? misplacing bound cause seg fault-- wrong in using nested for-loop this?

the professor provided clock functions, i'm hoping that's not problem. i'm running code in cygwin, problem? source code follows. using c99 standard well.

to clear: looking understanding (and fixing) reason code produces seg fault.

#include <stdio.h> #include <time.h> int main(void){    //first define array , 2 doubles count elapsed seconds.       double rowmajor, colmajor;    rowmajor = colmajor = 0;    int majorarray [1000][1000] = {};     clock_t start, end;     //set perform test 100 times.    for(int k = 0; k<10; k++)    {    start=clock();    //first row major    for(int = 0; < 1000; i++)    {        for(int j = 0; j<1000; j++)        {            majorarray[i][j] = 314;        }    }    end=clock();    rowmajor+= (end-start)/(double)clocks_per_sec;    //at point, we've done rowmajor, elapsed = rowmajor    start=clock();    //now column major      for(int = 0; < 1000; i++)    {        for(int j = 0; j<1000; j++)        {            majorarray[j][i] = 314;        }    }    end=clock();    colmajor += (end-start)/(double)clocks_per_sec;    }    //now we've done calculations 100 times, can compare values.    printf("row major took %f seconds\n", rowmajor);    printf("column major took %f seconds\n", colmajor);    if(rowmajor<colmajor)    {      printf("row major faster\n");    }    else    {       printf("column major faster\n");    }     return 0;  } 

your program works correctly on computer (x86-64/linux) suspect you're running system-specific limit on size of call stack. don't know how stack on cygwin, array 4,000,000 bytes (with 32-bit int) - big.

try moving declaration of majorarray out of main (put right after #includes) -- global variable, comes different allocation pool can bigger.

by way, comparison backwards:

if(rowmajor>colmajor) {   printf("row major faster\n"); } else {    printf("column major faster\n"); } 

also, test ought repeat process many different array sizes , shapes.