标签：c style class blog code java
原题地址：https://oj.leetcode.com/problems/first-missing-positive/
题意：
Given an unsorted integer array, find the first missing positive integer.
For
example,
Given [1,2,0] return 3,
and [3,4,-1,1] return 2.
Your algorithm should run in O(n) time and uses constant space.
解题思路：要求时间复杂度为O(n)和常数空间。又是一个tricky的解法。
class Solution: # @param A, a list of integers # @return an integer # @a very subtle solution def firstMissingPositive(self, A): n=len(A) for i in range(n): if A[i]<=0: A[i]=n+2 for i in range(n): if abs(A[i])<=n: curr=abs(A[i])-1 A[curr]=-abs(A[curr]) for i in range(n): if A[i]>0: return i+1 return n+1
[leetcode]First Missing Positive @ Python,布布扣,bubuko.com
[leetcode]First Missing Positive @ Python
标签：c style class blog code java
原文地址：http://www.cnblogs.com/zuoyuan/p/3777496.html
