Give an integer array，find the longest increasing continuous subsequence in this array.

An increasing continuous subsequence:

• Can be from right to left or from left to right.
• Indices of the integers in the subsequence should be continuous.

 Notice

O(n) time and O(1) extra space.

Have you met this question in a real interview? 

Yes

Example

For [5, 4, 2, 1, 3], the LICS is [5, 4, 2, 1], return 4.

For [5, 1, 2, 3, 4], the LICS is [1, 2, 3, 4], return 4.

 

这道题跟LeetCode上那道很像，但是比那道题简单，因为这道题需要递增子序列连续，这样我们只要挨个比较一下即可，由于题目中说了左右两个方向递增都行，可以用左右两个方向分别遍历一遍，也可以把两个遍历合并到一起，只用一个循环，同时寻找递增和递减的数列，使用两个变量cnt1和cnt2分别记录最长递增和递减数列的长度，一旦递增递减断开，记得将对应的计数器重置即可，参见代码如下：

 

class Solution {public:    /**     * @param A an array of Integer     * @return  an integer     */    int longestIncreasingContinuousSubsequence(vector
     
      & A) {        if (A.empty()) return 0;        int res = 1, cnt1 = 1, cnt2 = 1;        for (int i = 0; i < A.size() - 1; ++i) {            if (A[i] < A[i + 1]) {                ++cnt1;                 cnt2 = 1;            } else {                ++cnt2;                cnt1 = 1;            }            res = max(res, max(cnt1, cnt2));        }        return res;    }};
     

 

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