P1914 Little Book Boy-Caesar's Code (Java)

Little Book Boy-Caesar's Code

Subject link: https://www.luogu.com.cn/problem/P1914

Topic background

A certain Konjac became obsessed with the "little book boy", and one day he forgot his password when logging in (he did not bind his email or cell phone), so he threw the question to Shen Ben you.

Title description

Although Konjac has forgotten his password, he still remembers that the password is composed of a character string. The password is formed by moving back each letter in the original string (consisting of no more than 50 lowercase letters) by nn bits. The next letter of z is a, and so on. He has now found the original text string and nn before the move, please find the password.

Input format

The first line: n. The second line: a string of letters before moving

Output format

One line is the password of this Konjac

Sample input and output

Enter #1

1
qwe

Output #1

rxf

Problem-solving ideas:

((c[i]-'a' + n)% 26 +'a') Perform shift letter conversion, pay attention to type conversion.

code show as below:

import java.util.Scanner;

public class Main {
    
    
	public static void main(String[] args) {
    
    
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		String s = sc.next();
		char[] c = s.toCharArray();
		for (int i = 0; i < s.length(); i++) {
    
    
			c[i] = (char) ((c[i] - 'a' + n) % 26 + 'a');
			System.out.print(c[i]);
		}
		System.out.println();
	}
}