Added solution for Challenge 1

Challenge-1/README.md

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+saheed muhammed

Challenge-2/solution.py

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+class Solution:
+    def twoSum(self, nums: List[int], target: int) -> List[int]:
+        prev_map=dict()
+        for i, num in enumerate(nums):
+            if target - num in prev_map:
+               return[i, prev_map[target-num]]
+            prev_map[num]=i
+
+        return -1     

Challenge-4/Duplicate.py

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+class Solution:
+    def containsDuplicate(self, nums: List[int]) -> bool:
+        hash_set=set()
+
+        for num in nums:
+            if num in hash_set:
+                return True
+            hash_set.add(num)
+        return False

Challenge-5/solution.js

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+/**
+ * @param {number} a
+ * @param {number} b
+ * @return {number}
+ */
+var getSum = function(a, b) {
+
+    while(b){
+      let temp=a
+      a=temp^b
+      b=(temp&b)<<1 
+    }
+    return a
+
+
+};

Challenge_3/solution.py

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+class Solution:
+    def maxProfit(self, prices: List[int]) -> int:
+        # tow pointer
+        left, right = 0, 1
+        profit = 0
+
+        while right < len(prices):
+        # Check if profitable
+            if prices[right] > prices[left]:
+                profit = max(profit, prices[right] - prices[left])
+            else:
+                left = right  # Update left pointer to the current right 
+
+            right += 1  # Move the right pointer forward
+
+        return profit