/*
Copyright 2016 Grady Moran

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

/*
* A simple caesar cipher program to print all 26 character rotations of an input string.
*/

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

int main(int argc, char * args[])
{
	if (argc != 2){
		printf("Usage: rot_n \"INPUT_STRING\"\n");
		return 1;
	}

	int total_len = (strlen(args[1]) + 1);

	char inputstr[total_len];
	strcpy(inputstr, args[1]);
	
	char strings[25][total_len]; //array to hold all 25 rotated strings, to be printed later

	int i, j;
	//i tracks current rotation number (= 1 less than number rotations to perform this iteration)
	//j tracks index in input string to perform operation on
	for (i = 0; i < 25; i++){
		for (j = 0; j < total_len; j++){
			if (inputstr[j] >= 65 && inputstr[j] <= 90){ //UPPER
				strings[i][j] = ((inputstr[j] - 'A' + i + 1) % 26) + 'A';
			} else if (inputstr[j] >= 97 && inputstr[j] <= 122) { //lower
				strings[i][j] = ((inputstr[j] - 'a' + i + 1) % 26) + 'a';
			} else { //special character
				strings[i][j] = inputstr[j];
			}	
		}
		strings[i][strlen(inputstr)] = '\0'; //must terminate our strings
	}

	printf("%s\n", inputstr); //makes output easier to read if input string printed again
	for (i = 0; i < 25; i++){ //print them all
		printf("%s\n", strings[i]);
	}
	return 0;
}