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+/**
+* 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 MonotonicArray896 {
+public boolean isMonotonic(int[] A) {
+if (A == null || A.length <= 2) return true;
+int i = 1;
+int len = A.length;
+while (i < len && A[i] == A[i-1]) i++;
+if (i == len) return true;
+boolean flag = A[i] > A[i-1];
+while (i < len) {
+if (A[i] != A[i-1] && flag != A[i] > A[i-1]) return false;
+i++;
+}
+return true;
+}
+
+/**
+* https://leetcode.com/problems/monotonic-array/solution/
+*/
+public boolean isMonotonic2(int[] A) {
+int store = 0;
+for (int i = 0; i < A.length - 1; ++i) {
+int c = Integer.compare(A[i], A[i+1]);
+if (c != 0) {
+if (c != store && store != 0)
+return false;
+store = c;
+}
+}
+return true;
+}
+}