标签：style blog http java color 使用
Given an unsorted array of integers, find the length of the longest consecutive elements sequence.
For example,
Given [100, 4, 200, 1, 3, 2],
The
longest consecutive elements sequence is [1, 2, 3, 4]. Return
its length: 4.
Your algorithm should run in O(n) complexity.
使用容器实现。已经判断过的不用再次判断。
1 class Solution { 2 public: 3 int longestConsecutive(vector<int> &num) { 4 map<int, int> mp; 5 for (int i = 0; i < num.size(); ++i) { 6 mp[num[i]] = 1; 7 } 8 int len = 0, tmp; 9 for (int i = 0; i < num.size(); ++i) { 10 tmp = 1; 11 if (mp[num[i]] == 1) { 12 int left = num[i] - 1; 13 while (mp.count(left) && mp[left] == 1) { 14 mp[left--] = 0; 15 ++tmp; 16 } 17 int right = num[i] + 1; 18 while (mp.count(right) && mp[right] == 1) { 19 mp[right++] = 0; 20 ++tmp; 21 } 22 len = (len > tmp) ? len : tmp; 23 } 24 } 25 return len; 26 } 27 };
[Leetcode] Longest Consecutive Sequence,码迷,mamicode.com
[Leetcode] Longest Consecutive Sequence
标签：style blog http java color 使用
原文地址：http://www.cnblogs.com/easonliu/p/3699679.html
