转:http://blog.csdn.net/nanjunxiao/article/details/12973173 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…

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. 这道题让我们找缺失的首个正数,由于限定了O(n)的时间,所以一般的排序方法都不能用,最开始我没有看到还限…

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. 给定无序整型数组,找出第一个不在数组里的正整数,要求时间复杂度为O(n),空间复杂度为O(1) 本题使用…

First Missing Positive 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. 通过swap操作,把各个元素swap到相应的位置上,然后再…

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. 思路: 又是一个不让排序,但是要得到跟排序有关信息的.想了半天,只能空间换时间,可是又只能用常量空间,这…

41. First Missing Positive Problem's Link ---------------------------------------------------------------------------- Mean: 给你一组整数,找出第一个空缺的正整数. 要求:时间O(n),空间O(n). analyse: 这题时间O(n)想了半天没想到,用O(n*logn)过的. 然后看了discuss,想法非常巧妙,自愧不如. Time complexity: O(N) v…

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. 分析: 因为数组的大小为n,因此那个缺失的整数只可能的范围[1,n+1] 方法一:需要O(n)的空间,设…

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. 解题思路一: 刚看到题目的时候感觉无从下手,后来仔细理解题意,需要找到first missing p…

题目来源 https://leetcode.com/problems/first-missing-positive/ 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…

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. 这道题求的是在一个乱序数组中缺少的第一个正数,要求时间复杂度o(n)空间复杂度为1. 先上代码 pack…