Create partition-equal-subset-sum.py

Author: kamyu104

Python/partition-equal-subset-sum.py

@@ -0,0 +1,42 @@
+# Time:  O(n * s), s is the sum of nums
+# Space: O(s)
+
+# Given a non-empty array containing only positive integers,
+# find if the array can be partitioned into two subsets
+# such that the sum of elements in both subsets is equal.
+#
+# Note:
+# Both the array size and each of the array element will not exceed 100.
+#
+# Example 1:
+#
+# Input: [1, 5, 11, 5]
+#
+# Output: true
+#
+# Explanation: The array can be partitioned as [1, 5, 5] and [11].
+# Example 2:
+#
+# Input: [1, 2, 3, 5]
+#
+# Output: false
+#
+# Explanation: The array cannot be partitioned into equal sum subsets.
+
+class Solution(object):
+    def canPartition(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: bool
+        """
+        s = sum(nums)
+        if s % 2:
+            return False
+
+        dp = [False] * (s/2 + 1)
+        dp[0] = True
+        for num in nums:
+            for i in xrange(1, len(dp)):
+                if num <= i:
+                    dp[i] = dp[i] or dp[i - num]
+        return dp[-1]