C++ Simple and Short O(n) Solution, faster than 97%
At first, we will initialize the resulting string in the target size with \'a\'s.\nSo we used \'n\' out of the target \'k\' - we can reduce n from k.\nThen, we 
At first, we will initialize the resulting string in the target size with \'a\'s.\nSo we used \'n\' out of the target \'k\' - we can reduce n from k.\nThen, we go from left to right and while k > 0 we turn the \'a\'s to \'z\'s, then there might be a middle character with some letter that equals to the leftover of k.\nOur string in general will look like this: a...a?z...z, where ? is any letter.\n```\nclass Solution {\npublic:\n    string getSmallestString(int n, int k) {\n        string res(n, \'a\');\n        int ptr = n-1;\n        \n        k -= n;\n        while (k > 0) {\n            res[ptr--] += min(k, 25);\n            k -= min(k, 25);\n        }\n        \n        return res;\n    }\n};\n```\n**Like it? please upvote...**
['C']