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
Note:
1 <= A.length <= 50000 -100000 <= A[i] <= 100000
public class Solution {
public bool IsMonotonic(int[] A) {
if(A.Length<=1){
return true;
}
bool inc = true;
bool dec = true;
for(int i=1;i<A.Length;i++){
inc = inc && A[i-1]<=A[i];
dec = dec && A[i-1]>=A[i];
}
return inc || dec;
}
}Time Complexity: O(n)
Space Complexity: O(1)
