diff --git a/src/leetcode/array.md b/src/leetcode/array.md
index 0a0e30a..26fb10f 100644
--- a/src/leetcode/array.md
+++ b/src/leetcode/array.md
@@ -1 +1,31 @@
-# Array
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+# Array
+
++ [Squares of a Sorted Array](#squares-of-a-sorted-array)
+
+## Squares of a Sorted Array
+https://leetcode.com/problems/squares-of-a-sorted-array/
+```java
+class Solution {
+    public int[] sortedSquares(int[] A) {
+        if (A == null) return null;
+
+        int [] ans = new int[A.length];
+
+        int start = 0, end = A.length - 1;
+        int i = end; // insert position.
+        while (start <= end) {
+            int startPower = A[start] * A[start];
+            int endPower = A[end] * A[end];
+            if (startPower > endPower) {
+                ans[i--] = startPower;
+                start++;
+            } else {
+                ans[i--] = endPower;
+                end--;
+            }
+        }
+        return ans;
+    }
+}
+
+```
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