PartA

PartA1

using pointer to pointer impl 2D array

int **pp = malloc(sizeof(int*)*row);
for (int i =0;i < col;i++)
    pp[i] = malloc(sizeof(int)*col);

this snippet occurs frequently, but what difference between pp[0] and pp?
as we all know the array name is equivalent with the first element in array.

free() priority

linux command diff

scanf

PartA2

PartB