Skip 'a' & change until next 'a' || Very simple & easy to understand solution
 Up vote if you like the solution \n\n# Approach\n1. Skip all initial \'a\' from start.\n2. Check if you reach to end, then replace the last char with \'z\' and
<b> Up vote if you like the solution </b>\n\n# Approach\n1. Skip all initial \'a\' from start.\n2. Check if you reach to end, then replace the last char with \'z\' and  return it as ans. ( We need to do this as it is required to perform exactly one operation )\n3. If above is not the case keep on changeing each char to previous untill found \'a\' or reached the end.\n4. Return final s as ans.\n\n# Code\n```\nstring smallestString(string s) {\n    int i = 0;\n    while(i < s.size() && s[i] == \'a\') i++;\n    if(i >= s.size()) { s[s.size()-1] = \'z\'; return s; }\n    while(i < s.size() && s[i] != \'a\') { s[i]--; i++; }\n    return s;\n}\n```\n\n<b>Here is an article of my recent interview experience at Amazon, you may like :\nhttps://leetcode.com/discuss/interview-experience/3171859/Journey-to-a-FAANG-Company-Amazon-or-SDE2-(L5)-or-Bangalore-or-Oct-2022-Accepted
['C++']