Shifting Letters

 https://leetcode.com/problems/shifting-letters/

class Solution {
public:
    string shiftingLetters(string s, vector<int>& shifts) {
         long long shift=0;
        for(int i=s.size()-1;i>=0;i--){
            s[i]=((s[i]-'a')+(shift+shifts[i]) % 26) % 26 +'a';
            shift+=shifts[i];
        }
        return s;
    }
}; 

class Solution {
public:
    string shiftingLetters(string s, vector<int>& shifts) {
         int sum=0;
        for(int i=shifts.size()-1;i>=0;i--)
        {
            sum+=shifts[i]%26;
            s[i]='a'+((s[i]-'a')+sum)%26;
            
        }
        return s;
    }
};