Merge pull request #2923 from PritomKarmokar/cpp-solution-sqrt-x

adding 0069-sqrtx.cpp

Author: felivalencia3

cpp/0069-sqrtx.cpp

@@ -0,0 +1,22 @@
+class Solution {
+public:
+    int mySqrt(int x) {
+
+        int l = 0;
+        int r = x;
+
+        while(l <= r){
+            long int m = (l + r) / 2;
+            if(m * m == x){
+                return m;
+            }
+            else if(m * m > x){
+                r = m - 1;
+            }
+            else{
+                l = m + 1;
+            }
+        }
+        return r;
+    }
+};