Merge pull request #67 from zhanary/master

Update solution 014 [Python2]-20ms

Author: yanglbme

Solution2.py

@@ -0,0 +1,10 @@
+class Solution(object):
+    def longestCommonPrefix(self, strs):
+        if not strs:
+            return ""
+        for i,group in enumerate(zip(*strs)):#把字符串变成一个字母一个字母的格式
+            if len(set(group))>1: #集合里多于一个字符
+                return strs[0][:i] #输出0到目前编号位的字符
+        else:
+                return min(strs) #其他情况
+

solution/001.Two Sum/Solution2.py

@@ -1,4 +1,4 @@
-#time 32ms
+#time 32ms with python2
 class Solution(object):
     def twoSum(self, nums, target):
         buff = {}

solution/007.Reverse Integer/Solution2.py

@@ -0,0 +1,8 @@
+#36ms with python2
+class Solution:
+    def reverse(self, x):
+        s = cmp(x,0)       #提取此输入数字的符号
+        r = int(`x*s`[::-1])      #先作为字符串输入，然后转回整型
+        return r*s * (r<2**31)          #防止溢出，小于的情况下返回true，否则为false
+     
+

solution/013.Roman to Integer/Solution2.py

@@ -1,3 +1,4 @@
+# 80ms with python2
 class Solution(object):
     def romanToInt(self, s):
         dict = {'M':1000, 'D':500, 'C':100, 'L':50, 'X':10, 'V':5, 'I':1}   #对应关系存在一个字典里