845. 数组中的最长山脉

845. 数组中的最长山脉

 

 

 

class Solution {
public:
	bool confine = false, begin = false;
	int longestMountain(vector<int>& A) 
	{
		if (A.size()<3)
		{
			return 0;
		}
		vector<int>num = A;
		int ans = 0, left = 0, len = 0;
		for (int right = 0; right < num.size()-1; right++)
		{
			if (!begin)
			{
				if (num[right] < num[right + 1])
				{
					len++;
					left = right;
					begin = true;
				}
			}
			else
			{
				if (!confine)
				{
					if (num[right] > num[right + 1])
					{
						confine = true;
					}
					else if (num[right] == num[right + 1])
						begin = 0;
				}
				else
				{
					 if (num[right] <= num[right + 1])
					{
						confine = 0;
						begin = 0;
						ans = max(ans, right - left + 1);
						right--;
					 }
				}

			}
		}
		if (begin&&confine)
		{		
			ans = max(ans, (int)num.size() - left);
		}
		return ans;
	}
};