diff --git a/cpp/1299-Replace-Elements-with-Greatest-Element-on-Right-Side.cpp b/cpp/1299-Replace-Elements-with-Greatest-Element-on-Right-Side.cpp
new file mode 100644
index 000000000..0116ad06a
--- /dev/null
+++ b/cpp/1299-Replace-Elements-with-Greatest-Element-on-Right-Side.cpp
@@ -0,0 +1,17 @@
+class Solution {
+public:
+    vector<int> replaceElements(vector<int>& arr) {
+    // O(N) Time Complexity , O(1) Space complexity
+      int n = arr.size();
+      int maxSoFar = arr[n-1];
+      arr[n-1] = -1;
+      
+      for(int i=n-2;i>=0;i--)
+      {
+        int temp = maxSoFar;
+        if(maxSoFar < arr[i]) maxSoFar = arr[i];
+        arr[i] = temp;
+      }
+      return arr;
+    }
+};
diff --git a/cpp/392-Is-Subsequence.cpp b/cpp/392-Is-Subsequence.cpp
new file mode 100644
index 000000000..7bf6aa9df
--- /dev/null
+++ b/cpp/392-Is-Subsequence.cpp
@@ -0,0 +1,19 @@
+// Time Complexity is O(N) where n is the size of the target string.
+// Space Complexity is O(1)
+
+class Solution {
+public:
+   bool isSubsequence(string s, string t) {
+      int i = 0 , j = 0;
+      while(j < s.size() && i < t.size())
+      {
+        if(s[j] == t[i])
+          j++;
+        
+       i++;
+      }
+      
+      if(j >= s.size()) return true;
+      return false;
+    }
+};