leet code two-sum solution

id 1

Relates sashaaero#1

leet_1.py

@@ -0,0 +1,21 @@
+# https://leetcode.com/problems/two-sum
+# Runtime: 32 ms, faster than 90.53% of Python online submissions for Two Sum.
+
+class Solution(object):
+    def twoSum(self, nums, target):
+        """
+        :type nums: List[int]
+        :type target: int
+        :rtype: List[int]
+        """
+        h = {}
+        for i, num in enumerate(nums):
+            n = target - num
+            if n not in h:
+                h[num] = i
+            else:
+                return [h[n], i]
+
+if __name__ == '__main__':
+    s = Solution()
+    assert s.twoSum([2,7,11,15], 9) == [0,1]