LeetCode 674. Longest Continuous Increasing Subsequence

Longest Continuous Increasing Subsequence

题目描述:

Given an unsorted array of integers, find the length of longest 

continuous

 increasing
subsequence.

Example 1:

Input: [1,3,5,4,7]
Output: 3
Explanation: The longest continuous increasing subsequence is [1,3,5], its length is 3.
Even though [1,3,5,7] is also an increasing subsequence, it's not a continuous one where 5 and 7 are separated by 4.

Example 2:

Input: [2,2,2,2,2]
Output: 1
Explanation: The longest continuous increasing subsequence is [2], its length is 1.

题目大意:

给定一个序列，找出最长连续上升子序列，注意是上升序列，不是非递减即等于是不符合条件的。还有个重要的条件是连续。

试想，如果当前元素要比上一个元素大，那么他就能添加到上一个元素大后面，组成更上的连续上升子序列，我们设len[i]表示i位置以前包含i元素能组成的最长上升子序列，那么len[i] = len[i] + 1; 当然要复合前提条件nums[i] > nums[i-1]。于是我们在数组len中找到最大值输出即可。

题目代码:

class Solution {
public:
int findLengthOfLCIS(vector<int>& nums) {
if(nums.size() == 0) return 0;
if(nums.size() == 1) return 1;

vector<int> len(nums.size());
int maxn = INT_MIN;
for(int i = 0; i < nums.size(); i++){
len[i] = 1;
}
for(int i = 1; i < nums.size(); i++){
if(nums[i] > nums[i-1]){
len[i] = len[i-1]+1;
}
maxn = max(maxn, len[i]);
}
return maxn;
}
};