标签：
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：用桶排序。重复使用所给的空间。
public class Solution { public int firstMissingPositive(int[] nums) { for(int i=0;i<nums.length;i++){ if(nums[i]>0&&nums[i]<nums.length&&nums[i]!=nums[nums[i]-1]){ int temp=nums[nums[i]-1]; nums[nums[i]-1]=nums[i]; nums[i]=temp; i--; } } for(int j=0;j<nums.length;j++){ if(nums[j]!=j+1) return j+1; } return nums.length+1; } }
LeetCode 41:First Missing Positive Number
标签：
原文地址：http://www.cnblogs.com/gonewithgt/p/4566114.html
