C++ :

#include<iostream>
using namespace std;
int main()
{
	string keyboard = "1234567890-=qwertyuiop[]\\asdfghjkl;'zxcvbnm,./";
	string s;
	cin>>s;
	for(int i=0;s[i];i++)
	{
		int idx=keyboard.find(s[i]);
		cout<<keyboard[idx-1];
	}
	return 0;
}

Java :

import java.util.*;
public class Main {
	public static void main(String[] args) {
		Scanner input=new Scanner(System.in);
		String n=input.next();
		String t[]=new String[n.length()];
		
		String k[]= {"q","w","e","r","t","y","u","i","o","p","[","a","s","d","f","g","h","j","k","l",";","z","x","c","v","b","n","m",","};
		for(int i=0;i<n.length();i++) {			
			for(int j=0;j<k.length;j++) {
				t[i]=n.substring(i,i+1);
				if(t[i].equals(k[j])) {
					System.out.print(k[j-1]);
					break;
				}
				
			}
		}
	}
}