update at 2018-05-02

Author: bonfy

008-string-to-integer-atoi/string-to-integer-atoi.py

@@ -12,7 +12,11 @@
 # If no valid conversion could be performed, a zero value is returned.
 #
 # Note:
-# Assume we are dealing with an environment which could only store integers within the 32-bit signed integer range: [−231,  231 − 1]. If the numerical value is out of the range of representable values, INT_MAX (231 − 1) or INT_MIN (−231) is returned.
+#
+#
+# 	Only the space character ' ' is considered as whitespace character.
+# 	Assume we are dealing with an environment which could only store integers within the 32-bit signed integer range: [−231,  231 − 1]. If the numerical value is out of the range of representable values, INT_MAX (231 − 1) or INT_MIN (−231) is returned.
+#
 #
 # Example 1:
 #

134-gas-station/gas-station.py

@@ -1,21 +1,56 @@
 # -*- coding:utf-8 -*-
 
 
-#
 # There are N gas stations along a circular route, where the amount of gas at station i is gas[i].
 #
+# You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from station i to its next station (i+1). You begin the journey with an empty tank at one of the gas stations.
 #
+# Return the starting gas station's index if you can travel around the circuit once in the clockwise direction, otherwise return -1.
 #
-# You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from station i to its next station (i+1). You begin the journey with an empty tank at one of the gas stations.
+# Note:
 #
 #
+# 	If there exists a solution, it is guaranteed to be unique.
+# 	Both input arrays are non-empty and have the same length.
+# 	Each element in the input arrays is a non-negative integer.
 #
-# Return the starting gas station's index if you can travel around the circuit once, otherwise return -1.
 #
+# Example 1:
 #
 #
-# Note:
-# The solution is guaranteed to be unique.
+# Input: 
+# gas  = [1,2,3,4,5]
+# cost = [3,4,5,1,2]
+#
+# Output: 3
+#
+# Explanation:
+# Start at station 3 (index 3) and fill up with 4 unit of gas. Your tank = 0 + 4 = 4
+# Travel to station 4. Your tank = 4 - 1 + 5 = 8
+# Travel to station 0. Your tank = 8 - 2 + 1 = 7
+# Travel to station 1. Your tank = 7 - 3 + 2 = 6
+# Travel to station 2. Your tank = 6 - 4 + 3 = 5
+# Travel to station 3. The cost is 5. Your gas is just enough to travel back to station 3.
+# Therefore, return 3 as the starting index.
+#
+#
+# Example 2:
+#
+#
+# Input: 
+# gas  = [2,3,4]
+# cost = [3,4,3]
+#
+# Output: -1
+#
+# Explanation:
+# You can't start at station 0 or 1, as there is not enough gas to travel to the next station.
+# Let's start at station 2 and fill up with 4 unit of gas. Your tank = 0 + 4 = 4
+# Travel to station 0. Your tank = 4 - 3 + 2 = 3
+# Travel to station 1. Your tank = 3 - 3 + 3 = 3
+# You cannot travel back to station 2, as it requires 4 unit of gas but you only have 3.
+# Therefore, you can't travel around the circuit once no matter where you start.
+#
 #
 
 

136-single-number/single-number.py

@@ -1,12 +1,26 @@
 # -*- coding:utf-8 -*-
 
 
-# Given an array of integers, every element appears twice except for one. Find that single one.
-#
+# Given a non-empty array of integers, every element appears twice except for one. Find that single one.
 #
 # Note:
+#
 # Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?
 #
+# Example 1:
+#
+#
+# Input: [2,2,1]
+# Output: 1
+#
+#
+# Example 2:
+#
+#
+# Input: [4,1,2,1,2]
+# Output: 4
+#
+#
 
 
 class Solution(object):

137-single-number-ii/single-number-ii.py

@@ -1,13 +1,24 @@
 # -*- coding:utf-8 -*-
 
 
+# Given a non-empty array of integers, every element appears three times except for one, which appears exactly once. Find that single one.
 #
-# Given an array of integers, every element appears three times except for one, which appears exactly once. Find that single one.
+# Note:
 #
+# Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?
 #
+# Example 1:
 #
-# Note:
-# Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?
+#
+# Input: [2,2,3,2]
+# Output: 3
+#
+#
+# Example 2:
+#
+#
+# Input: [0,1,0,1,0,1,99]
+# Output: 99
 #
 
 

189-rotate-array/rotate-array.py

@@ -1,22 +1,35 @@
 # -*- coding:utf-8 -*-
 
 
-# Rotate an array of n elements to the right by k steps.
+# Given an array, rotate the array to the right by k steps, where k is non-negative.
 #
-# For example, with n = 7 and k = 3, the array [1,2,3,4,5,6,7] is rotated to [5,6,7,1,2,3,4].
+# Example 1:
 #
-# Note:
-# Try to come up as many solutions as you can, there are at least 3 different ways to solve this problem.
 #
-# [show hint]
+# Input: [1,2,3,4,5,6,7] and k = 3
+# Output: [5,6,7,1,2,3,4]
+# Explanation:
+# rotate 1 steps to the right: [7,1,2,3,4,5,6]
+# rotate 2 steps to the right: [6,7,1,2,3,4,5]
+# rotate 3 steps to the right: [5,6,7,1,2,3,4]
+#
+#
+# Example 2:
+#
+#
+# Input: [-1,-100,3,99] and k = 2
+# Output: [3,99,-1,-100]
+# Explanation: 
+# rotate 1 steps to the right: [99,-1,-100,3]
+# rotate 2 steps to the right: [3,99,-1,-100]
+#
+#
+# Note:
 #
-# Hint:
-# Could you do it in-place with O(1) extra space?
 #
-# Related problem: Reverse Words in a String II
+# 	Try to come up as many solutions as you can, there are at least 3 different ways to solve this problem.
+# 	Could you do it in-place with O(1) extra space?
 #
-# Credits:
-# Special thanks to @Freezen for adding this problem and creating all test cases.
 #
 
 

206-reverse-linked-list/reverse-linked-list.py

@@ -3,9 +3,15 @@
 
 # Reverse a singly linked list.
 #
-# click to show more hints.
+# Example:
+#
+#
+# Input: 1->2->3->4->5->NULL
+# Output: 5->4->3->2->1->NULL
+#
+#
+# Follow up:
 #
-# Hint:
 # A linked list can be reversed either iteratively or recursively. Could you implement both?
 #
 

README.md

@@ -1,9 +1,9 @@
 # :pencil2: Leetcode Solutions with Python,Javascript
-Update time:  2018-04-20 17:17:06
+Update time:  2018-05-02 09:30:43
 
 Auto created by [leetcode_generate](https://github.com/bonfy/leetcode)
 
-I have solved **97   /   734** problems
+I have solved **97   /   742** problems
 while there are **133** problems still locked.
 
 If you want to use this tool please follow this [Usage Guide](https://github.com/bonfy/leetcode/blob/master/README_leetcode_generate.md)
@@ -750,3 +750,11 @@ If you are loving solving problems in leetcode, please contact me to enjoy it to
 |835|[linked-list-components](https://leetcode.com/problems/linked-list-components)||[:memo:](https://leetcode.com/articles/linked-list-components/)|Medium|
 |836|[race-car](https://leetcode.com/problems/race-car)||[:memo:](https://leetcode.com/articles/race-car/)|Hard|
 |837|[most-common-word](https://leetcode.com/problems/most-common-word)||[:memo:](https://leetcode.com/articles/most-common-word/)|Easy|
+|839|[short-encoding-of-words](https://leetcode.com/problems/short-encoding-of-words)||[:memo:](https://leetcode.com/articles/short-encoding-of-words/)|Medium|
+|841|[shortest-distance-to-a-character](https://leetcode.com/problems/shortest-distance-to-a-character)||[:memo:](https://leetcode.com/articles/shortest-distance-to-a-character/)|Easy|
+|842|[card-flipping-game](https://leetcode.com/problems/card-flipping-game)||[:memo:](https://leetcode.com/articles/card-flipping-game/)|Medium|
+|843|[binary-trees-with-factors](https://leetcode.com/problems/binary-trees-with-factors)||[:memo:](https://leetcode.com/articles/binary-trees-with-factors/)|Medium|
+|851|[goat-latin](https://leetcode.com/problems/goat-latin)||[:memo:](https://leetcode.com/articles/goat-latin/)|Easy|
+|852|[friends-of-appropriate-ages](https://leetcode.com/problems/friends-of-appropriate-ages)||[:memo:](https://leetcode.com/articles/friends-of-appropriate-ages/)|Medium|
+|853|[most-profit-assigning-work](https://leetcode.com/problems/most-profit-assigning-work)||[:memo:](https://leetcode.com/articles/most-profit-assigning-work/)|Medium|
+|854|[making-a-large-island](https://leetcode.com/problems/making-a-large-island)||[:memo:](https://leetcode.com/articles/making-a-large-island/)|Hard|