Create find-smallest-common-element-in-all-rows.py

Author: kamyu104

Python/find-smallest-common-element-in-all-rows.py

@@ -0,0 +1,35 @@
+# Time:  O(m * n)
+# Space: O(m)
+
+class Solution(object):
+    def smallestCommonElement(self, mat):
+        """
+        :type mat: List[List[int]]
+        :rtype: int
+        """
+        # values could be duplicated in each row
+        intersections = set(mat[0])
+        for i in xrange(1, len(mat)):
+            intersections &= set(mat[i])
+        return min(intersections or [-1])
+
+
+# Time:  O(m * n)
+# Space: O(m)
+import collections
+
+
+class Solution2(object):
+    def smallestCommonElement(self, mat):
+        """
+        :type mat: List[List[int]]
+        :rtype: int
+        """
+        # assumed value is unique in each row
+        counter = collections.Counter()
+        for row in mat:
+            for c in row:
+                counter[c] += 1
+                if counter[c] == len(mat):
+                    return c
+        return -1