/*
 *  reverseString takes a single command line argument as a string and
 *  reverses it.
 *
 *  Example: "123" is reversed to "321"
 *
 *  Time/space complexity: O(n)
 *
 */

#include <stdio.h>
#include <string.h>

int main (int argc, char* argv[]) {

    if (argc != 2) {
        printf ("\n\tOops! You might want to give me one string to reverse.\n\n");
    } else {

        char temp = 0;
        int tail = strlen(argv[1]) - 1;

        printf ("\nOriginal string = %s\n", argv[1]);

        for (int head = 0; head < tail; head++, tail--)
        {
            temp = argv[1][head];
            argv[1][head] = argv[1][tail];
            argv[1][tail] = temp;
        }

        printf ("Reversed string = %s\n", argv[1]);
    }
}