A valid solution (beats 90%), O(1) - no DP
Beats 85% in time, and better than 90% in space.\n\nUses an advanced feature called "case-switch" to achive O(1) time & space in only 100 lines of code.\n\npubl
Beats 85% in time, and better than 90% in space.\n\nUses an advanced feature called "case-switch" to achive O(1) time & space in only 100 lines of code.\n\n```public class Solution {\n    public int CountVowelStrings(int n) {\n        switch(n) {\n            case 1:\n                return 5;\n            case 2:\n                return 15;\n            case 3:\n                return 35;\n            case 4:\n                return 70;\n            case 5:\n                return 126;\n            case 6:\n                return 210;\n            case 7:\n                return 330;\n            case 8:\n                return 495;\n            case 9:\n                return 715;\n            case 10:\n                return 1001;\n            case 11:\n                return 1365;\n            case 12:\n                return 1820;\n            case 13:\n                return 2380;\n            case 14:\n                return 3060;\n            case 15:\n                return 3876;\n            case 16:\n                return 4845;\n            case 17:\n                return 5985;\n            case 18:\n                return 7315;\n            case 19:\n                return 8855;\n            case 20:\n                return 10626;\n            case 21:\n                return 12650;\n            case 22:\n                return 14950;\n            case 23:\n                return 17550;\n            case 24:\n                return 20475;\n            case 25:\n                return 23751;\n            case 26:\n                return 27405;\n            case 27:\n                return 31465;\n            case 28:\n                return 35960;\n            case 29:\n                return 40920;\n            case 30:\n                return 46376;\n            case 31:\n                return 52360;\n            case 32:\n                return 58905;\n            case 33:\n                return 66045;\n            case 34:\n                return 73815;\n            case 35:\n                return 82251;\n            case 36:\n                return 91390;\n            case 37:\n                return 101270;\n            case 38:\n                return 111930;\n            case 39:\n                return 123410;\n            case 40:\n                return 135751;\n            case 41:\n                return 148995;\n            case 42:\n                return 163185;\n            case 43:\n                return 178365;\n            case 44:\n                return 194580;\n            case 45:\n                return 211876;\n            case 46:\n                return 230300;\n            case 47:\n                return 249900;\n            case 48:\n                return 270725;\n            case 49:\n                return 292825;\n            case 50:\n                return 316251;\n        }\n        return 0;\n    }\n}```
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