Solution for 28th problem

C++/28_first_occurrence_in_a_string.cpp

@@ -0,0 +1,26 @@
+/**
+ * easy difficulty
+ * runtime: 0ms
+ * beats 100%
+ *
+ * memory: 8.85mb
+ * beats 99.68%
+ */
+
+class Solution {
+public:
+    /**
+     * @brief a function will return the index of the first occurence of
+     * a string in the main string
+     * @param haystack is the main string that the search will be applied to
+     * @param needle is the string that the function will search for
+     * @return the index of the first occurence of 'needle' in 'haystack' if
+     * found ; std::string::npos (or -1) otherwise
+     */
+    constexpr inline int strStr(const string& haystack, const string& needle) noexcept {
+        // using built in functions to find the index of the
+        // first occurence of the 'needle' in the 'haystack'
+        // and if 'needle' isn't present, it will return std::string::npos (-1)
+        return haystack.find(needle);
+    }
+};

README.md

@@ -294,9 +294,10 @@ Check out ---> [Sample PR](https://github.com/codedecks-in/LeetCode-Solutions/pu
 | --- | --------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------- | ---------------------- | ------------------ | ---------- | ----------- | ---------------- |
 | 005 | [Longest Palindromic Substring](https://leetcode.com/problems/longest-palindromic-substring/) | [Python](./Python/5_LongestPalindromicSubstring.py) <br> [JavaScript](./JavaScript/5.Longest-Palindromic-Substring.js) | _O(N^2)_ <br> _O(N^2)_ | _O(N)_ <br> _O(1)_ | Medium     |             | Expand the Wings |
 | 4   | [Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/)     | [Java](./Java/median-of-two-sorted-arrays.java)                                                                        | _O(log(min(m,n)))_     | _O(1)_             | Hard       |             |                  |
-| 845 | [Longest Mountain in Array](https://leetcode.com/problems/longest-mountain-in-array/)         | [C++](./C++/Longest-Mountain-in-Array.cpp)                                                                             | _O(N)_                 | _O(1)_             | Medium     | Two Pointer |
+| 845 | [Longest Mountain in Array](https://leetcode.com/problems/longest-mountain-in-array/)         | [C++](./C++/Longest-Mountain-in-Array.cpp)                                                                             | _O(N)_                 | _O(1)_             | Medium     | Two Pointer |                  |
 | 015 | [3 Sum](https://leetcode.com/problems/3sum/)                                                  | [C++](./C++/3sum.cpp)                                                                                                  | _O(N)_                 | _O(1)_             | Medium     | Two Pointer |                  |
 | 021 | [Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/)               | [C++](./C++/Longest-Mountain-in-Array.cpp)                                                                             | _O(N)_                 | _O(1)_             | Easy       | Two Pointer |                  |
+| 28  | [Find the Index of the First Occurence in a String](https://leetcode.com/problems/find-the-index-of-the-first-occurrence-in-a-string) | [C++](./C++/28_first_occurrence_in_a_string.cpp)                                | _O(1)_                 | _O(1)_             | Easy       | Two Pointer |                  |
 
 
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