diff --git a/BestTimeToBuySellStock.cpp b/BestTimeToBuySellStock.cpp
new file mode 100644
index 0000000..3b4df23
--- /dev/null
+++ b/BestTimeToBuySellStock.cpp
@@ -0,0 +1,20 @@
+class Solution {
+public:
+    int maxProfit(vector<int>& prices) {
+        int valley = INT_MAX;
+        int peak = INT_MIN;
+        int i=0;
+        int profit = 0;
+]
+        while (i< prices.size()-1) {
+            while (i<prices.size()-1 && prices[i] >= prices[i+1]) 
+                i++;
+            valley = prices[i];
+            while (i<prices.size()-1 && prices[i] <= prices[i+1]) // 
+                i++;
+            peak = prices[i];
+            profit += (peak-valley);
+        }
+        return profit;
+    }
+};
diff --git a/peekingIterator.cpp b/peekingIterator.cpp
new file mode 100644
index 0000000..ed4aace
--- /dev/null
+++ b/peekingIterator.cpp
@@ -0,0 +1,54 @@
+/*
+ * Below is the interface for Iterator, which is already defined for you.
+ * **DO NOT** modify the interface for Iterator.
+ *
+ *  class Iterator {
+ *		struct Data;
+ * 		Data* data;
+ *  public:
+ *		Iterator(const vector<int>& nums);
+ * 		Iterator(const Iterator& iter);
+ *
+ * 		// Returns the next element in the iteration.
+ *		int next();
+ *
+ *		// Returns true if the iteration has more elements.
+ *		bool hasNext() const;
+ *	};
+ */
+
+class PeekingIterator : public Iterator {
+public:
+    int nextEle;
+    int nextVal;
+	PeekingIterator(const vector<int>& nums) : Iterator(nums) {
+	    // Initialize any member here.
+	    // **DO NOT** save a copy of nums and manipulate it directly.
+	    // You should only use the Iterator interface methods.
+        nextEle = Iterator::hasNext();
+        if (nextEle) {
+            nextVal = Iterator::next();
+        }
+	}
+	
+    // Returns the next element in the iteration without advancing the iterator.
+	int peek() {
+        return nextVal;
+	}
+	
+	// hasNext() and next() should behave the same as in the Iterator interface.
+	// Override them if needed.
+	int next() {
+        int oldVal = nextVal;
+
+        nextEle = Iterator::hasNext();
+	    if (nextEle) {
+            nextVal = Iterator::next();
+        }
+        return oldVal;
+	}
+	
+	bool hasNext() const {
+	    return nextEle;
+	}
+};