Create smallest-range-ii.py

Python/smallest-range-ii.py

@@ -0,0 +1,46 @@
+# Time:  O(nlogn)
+# Space: O(1)
+
+# Given an array A of integers, for each integer A[i]
+# we need to choose either x = -K or x = K, and add x to A[i] (only once).
+#
+# After this process, we have some array B.
+#
+# Return the smallest possible difference
+# between the maximum value of B and the minimum value of B.
+#
+# Example 1:
+#
+# Input: A = [1], K = 0
+# Output: 0
+# Explanation: B = [1]
+# Example 2:
+#
+# Input: A = [0,10], K = 2
+# Output: 6
+# Explanation: B = [2,8]
+# Example 3:
+#
+# Input: A = [1,3,6], K = 3
+# Output: 3
+# Explanation: B = [4,6,3]
+#
+# Note:
+# - 1 <= A.length <= 10000
+# - 0 <= A[i] <= 10000
+# - 0 <= K <= 10000
+
+class Solution(object):
+    def smallestRangeII(self, A, K):
+        """
+        :type A: List[int]
+        :type K: int
+        :rtype: int
+        """
+        A.sort()
+        result = A[-1]-A[0]
+        for i in xrange(len(A)-1):
+            result = min(result,
+                         max(A[-1]-K, A[i]+K) -
+                         min(A[0]+K, A[i+1]-K))
+        return result