(Easy) Monotonic Array LeetCode

Description:

An array is monotonic if it is either monotone increasing or monotone decreasing.

An array A is monotone increasing if for all i <= j, A[i] <= A[j].  An array A is monotone decreasing if for all i <= j, A[i] >= A[j].

Return true if and only if the given array A is monotonic.

 

Example 1:

Input: [1,2,2,3]
Output: true

Example 2:

Input: [6,5,4,4]
Output: true

Example 3:

Input: [1,3,2]
Output: false

Example 4:

Input: [1,2,4,5]
Output: true

Example 5:

Input: [1,1,1]
Output: true

 

Solution:

class Solution {
    public boolean isMonotonic(int[] A) {
        
        if(A==null||A.length==0){
            return true;
        }
        
        return (Mono_Increase(A)||Mono_Decrease(A));
        
    }
    
    
    boolean Mono_Increase(int[] A){
        
        for(int i = 0; i< A.length-1; i++){
            
            if(A[i]>A[i+1]){
                return false;
            }
        }
        
        return true;
    }
    
        
    boolean Mono_Decrease(int[] A){
        
        for(int i = 0; i< A.length-1; i++){
            
            if(A[i]<A[i+1]){
                return false;
            }
        }
        
        return true;
    }
}