import java.util.*; 


public class Main {

	
	public static void main (String[] aurg) {
		
		String clearM = "INTRO TO COMPUTER PROGRAMMING II";
		System.out.println(clearM);
		String encrypM = null;
		int key = 7;
		encrypM = caesarEncoding(clearM, key);
		System.out.println("The encrypted message is = " + encrypM);
		
		System.out.println("Testing decription: ");
		caesarDecoding(encrypM,key);
	}
	
	
	

	
	//Encription function:
	// Take as input the clear message and the key
	// it returns the encrtypted message
	
	public static String caesarEncoding(String clearM, int key) {
		int[] uni = new int[clearM.length()];
		int[] uniEn = new int[clearM.length()];
		char[] chEn = new char[clearM.length()];
		char[] ch = clearM.toCharArray();


//		Encryption 
		for (int i = 0; i<clearM.length(); i++ ) {
			uni[i]=(int)ch[i];
			uniEn[i] = uni[i] + key;
			chEn[i] = (char)uniEn[i];
		}
		
		String encrypM = new String(chEn);
		return(encrypM);
	}
	
	
	
	
//Decription function:
// Take as input the encrypted message and the key
// it prints the clear message
// no output
	
	
	public static void caesarDecoding(String encrypM, int key) {
		int[] uniEn = new int[encrypM.length()];
		int[] uniDe = new int[encrypM.length()];
		char[] ch = new char[encrypM.length()];
		char[] chEn = encrypM.toCharArray();

//		Decryption 
		for (int i = 0; i<encrypM.length(); i++ ) {
			uniEn[i]=(int)chEn[i];
//			myPrint("uniEn" + i + " = " + uniEn[i]);
			uniDe[i]= uniEn[i]-key;
//			myPrint("uni" + i + " = " + uni[i]);
			ch[i]=(char)uniDe[i];
		}
		String clearM = new String(ch);

		System.out.println(clearM);
	}
	
	
	
	
	
}