Algorithm
Problem Name: 848. Shifting Letters
Problem Link: https://leetcode.com/problems/shifting-letters/
You are given a string s of lowercase English letters and an integer array shifts of the same length.
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', andshift('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.
Example 2:
Input: s = "aaa", shifts = [1,2,3] Output: "gfd"
Constraints:
1 <= s.length <= 105sconsists of lowercase English letters.shifts.length == s.length0 <= shifts[i] <= 109
Code Examples
#1 Code Example with C++ Programming
Code -
C++ Programming
class Solution {
public:
string shiftingLetters(string S, vector<int>& shifts) {
long sum = 0;
for(int i = S.size() - 1; i >= 0; sum += shifts[i--]) S[i] = 'a' + (S[i] - 'a' + sum + shifts[i]) % 26;
return S;
}
};
Input
Output
#2 Code Example with Java Programming
Code -
Java Programming
class Solution {
public String shiftingLetters(String s, int[] shifts) {
long totalShifts = 0;
StringBuilder sb = new StringBuilder();
for (int i = shifts.length - 1; i >= 0; i--) {
totalShifts += shifts[i];
sb.append(getShiftedChar(s.charAt(i), totalShifts));
}
return sb.reverse().toString();
}
private char getShiftedChar(char c, long shifts) {
long newAscii = ((int) c) + (shifts % 26);
return (char) (newAscii > 122 ? (97 + (newAscii - 122) - 1) : newAscii);
}
}
Input
Output
#3 Code Example with Javascript Programming
Code -
Javascript Programming
const shiftingLetters = function(S, shifts) {
let suffixSum = 0,
result = "";
for (let i = S.length - 1; i >= 0; i--) {
suffixSum += shifts[i];
let ascii = S[i].charCodeAt() - 97;
result = String.fromCharCode(97 + ((ascii + suffixSum) % 26)) + result;
}
return result;
};
Input
Output
#4 Code Example with Python Programming
Code -
Python Programming
class Solution:
def shiftingLetters(self, S, shifts):
sm, res = sum(shift % 26 for shift in shifts) % 26, ""
for i, s in enumerate(shifts):
move, sm = ord(S[i]) + sm % 26, sm - s
res += chr(move > 122 and move - 26 or move)
return res
Input
Output