If you are a beginner in programming it may be that you got some trouble to define an array of large size.As if you are trying to allocate an array of size (10^7===10000000) like int a[10000000]; you must got an run time error called segmentation fault.To overcome these difficulties we use a malloc function to declare a run time memory. First we have to include header file "malloc.h" and then the following lines of codes. #include<malloc.h> int main() { int *a; a=(int *)malloc(sizeof(int)*10000000); //equivalent to int a[10000000] without segmentation fault } If you want to declare a two dimensional array like.... int a[m][n]; Where m and n are very large number then write the following lines of codes. int main() { int **a,i; a=(int **)mall...