Shifting Letters LeetCode Solution - The Coding Shala

Home >> LeetCode >> Shifting Letters

 In this post, we will learn how to solve LeetCode's Shifting Letters Problem and will implement its solution in Java.

Shifting Letters Problem

We have a string S of lowercase letters, and an integer array shifts. Call the shift of a letter, the next letter in the alphabet, (wrapping around so that 'z' becomes 'a'). For example, shift('a') = 'b', shift('t') = 'u', and shift('z') = 'a'. Now for each shifts[i] = x, we want to shift the first i+1 letters of S, x times. Return the final string after all such shifts to S are applied.

Example 1:
Input: S = "abc", shifts = [3,5,9]
Output: "rpl"
Explanation: 
We start with "abc".
After shifting the first 1 letters of S by 3, we have "dbc".
After shifting the first 2 letters of S by 5, we have "igc".
After shifting the first 3 letters of S by 9, we have "rpl", the answer.

Practice this problem on LeetCode(Click Here).

Shifting Letters Java Solution

Approach 1

The last character of the string only shifts number shifts[length-1] times. The second last character of string shifts number shifts[length-1] + shifts[length-2] times, and like this first character shifts the sum of all the numbers in shifts array times.

Java Program: 

class Solution {
    public String shiftingLetters(String S, int[] shifts) {
        long currShift = 0;
        for(int i=0; i<shifts.length; i++) {
            currShift += shifts[i];
        }
        StringBuilder sb = new StringBuilder();
        long ch = S.charAt(0) - 97;
        if(currShift%26 != 0)
        ch = (ch + currShift) % 26;
        sb.append((char)( ch+97));
        for(int i=1; i<shifts.length; i++){
            currShift -= shifts[i-1];
            ch = S.charAt(i) - 97;
            if(currShift%26 != 0)
            ch = (ch + currShift)%26;
            sb.append((char) (ch+97));
        }
        return sb.toString();
    }
}


Other Posts You May Like
Please leave a comment below if you like this post or found some errors, it will help me to improve my content.

Comments

Popular Posts from this Blog

Shell Script to find sum, product and average of given numbers - The Coding Shala

Single Number 3 LeetCode Solution - The Coding Shala

LeetCode - Number of Good Pairs Solution - The Coding Shala

Shell Script to Create a Simple Calculator - The Coding Shala

Java Method Overloading - The Coding Shala