Adding cpp implementation for 17

Author: mdrazak2001

0017_letter_combinations_of_a_phone_number/letter_combinations.cpp

@@ -0,0 +1,43 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class Solution
+{
+public:
+    vector<string> m = {"", "", "abc", "def", "ghi", "jkl", "mno", "pqrs", "tuv", "wxyz"};
+    vector<string> ans;
+    vector<string> letterCombinations(string digits)
+    {
+        solve(0, "", digits);
+        return ans;
+    }
+    void solve(int i, string path, string digits)
+    {
+        if (i >= digits.size())
+        {
+            if (path.size() > 0)
+                ans.push_back(path);
+            return;
+        }
+        for (auto c : m[digits[i] - '0'])
+        {
+            path += c;
+            solve(i + 1, path, digits);
+            path.pop_back();
+        }
+    }
+};
+
+int main()
+{
+    cout << "Enter A string : ";
+    string s;
+    cin >> s;
+    Solution sol;
+    // vector<string> ans = sol.letterCombinations(s) ;
+    for (auto str : sol.letterCombinations(s))
+    {
+        cout << str << " ";
+    }
+    return 0;
+}