[Java] O(logN) Solution, Divide And Conquer, 3ms Faster than 100%
Use divide and conquer when adding \'a\' and \'z\'.\n\nclass Solution {\n    public String getSmallestString(int n, int k) {\n        int subK = k - n; \n      
Use divide and conquer when adding \'a\' and \'z\'.\n```\nclass Solution {\n    public String getSmallestString(int n, int k) {\n        int subK = k - n; \n        int numZ = subK / 25;\n        char mid = (char)(\'a\' + subK % 25);\n        int numA = n - numZ - 1;\n        \n        StringBuilder res = new StringBuilder();\n        res.append(repChar(\'a\', numA));\n        res.append(mid);\n        res.append(repChar(\'z\', numZ));\n        return res.toString();\n    }\n    \n    public String repChar(char c, int reps) {\n         StringBuilder adder = new StringBuilder(Character.toString(c));\n         StringBuilder result = new StringBuilder();\n         while (reps > 0) {\n             if (reps % 2 == 1) {\n                result.append(adder);\n             }\n             adder.append(adder);\n             reps /= 2;\n         } \n         return result.toString();\n    }\n}\n```\n\nI will add more explanation later...(Maybe)
['Divide and Conquer', 'Java']