countHi - Recursive

Given a string, compute recursively (no loops) the number of times lowercase "hi" appears in the string. countHi("xxhixx") → 1 countHi("xhixhix") → 2 countHi("hi") → 1

C# :

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public static int countHi(String str) { //stop condition if (str.Length < 2) return 0; //Process int index = str.IndexOf("hi"); if (index < 0) return 0; return 1 + countHi(str.Substring(index + 1, str.Length - (1 + index))); }

Result :

CountX - Recursive

Given a string, compute recursively (no loops) the number of lowercase 'x' chars in the string. countX("xxhixx") → 4 countX("xhixhix") → 3 countX("hi") → 0

Hisoka's Jutsu :

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public int countX(String str) { if (str.length() == 0) return 0; if(str.charAt(str.length()-1) == 'x') return 1+countX(str.substring(0, str.length()-1)); return countX(str.substring(0, str.length()-1)); }

Output :

Ooowh... btw... if we want to write countX in C#, it will gonna be like this :

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public static int countX(String str) { //stop condition if (str.Length == 0) return 0; if (str[(str.Length - 1)] == 'x') return 1 + countX(str.Substring(0, str.Length - 1)); return countX(str.Substring(0, str.Length - 1)); }

The output is same, you can check it here