To print an X using odd num input you can just print a square like,
*****
*****
*****
*****
*****
only print * if it's on the diagonals, and print a space otherwise!
#include<stdio.h>
#include<stdlib.h>
int main(int argc,char *argv[]){
int i;
int j;
int size=atoi(argv[1]);
for...