【Leetcode_easy】941. Valid Mountain Array

problem

941. Valid Mountain Array

solution:

class Solution {
public:
    bool validMountainArray(vector<int>& A) {
        if(A.size()<) return false;
        int max = A[], max_id = ;
        for(int i=; i<A.size(); ++i)
        {
            if(A[i]>max)
            {
                max = A[i];
                max_id = i;
            }
        }
        if(max_id== || max_id==A.size()-) return false;//errr..
        for(int i=; i<A.size(); i++)
        {
            if(i<max_id && A[i]<=A[i-]) return false;//errr...
            if(i>max_id && A[i]>=A[i-]) return false;//errr..
        }
        return true;
    }
};

solution2:

class Solution {
public:
    bool validMountainArray(vector<int>& A) {
        int i=, n=A.size()-, j=n;
        while(i<n- && A[i]<A[i+]) i++;
        while(j> && A[j-]>A[j]) j--;
        return i> && i==j && j<n;
    }
};

参考

1. Leetcode_easy_941. Valid Mountain Array;

2. discuss_climb_mountain;

完