[LeetCode 189] Rotate Array - Array

Author: HiiWee

hoseok/week80/LeetCode189.java

@@ -0,0 +1,39 @@
+import java.util.*;
+
+// Time Complexity: O(N), Space Complexity: O(1)
+class Solution {
+    public void rotate(int[] nums, int k) {
+        k %= nums.length;
+
+        reverse(nums, 0, nums.length - 1);
+        reverse(nums, 0, k - 1);
+        reverse(nums, k, nums.length - 1);
+    }
+
+    public void reverse(int[] nums, int l, int r) {
+        while (l < r) {
+            int temp = nums[l];
+            nums[l] = nums[r];
+            nums[r] = temp;
+            l++;
+            r--;
+        }
+    }
+}
+
+// Time Complexity: O(N), Space Complexity: O(N)
+class Solution {
+    public void rotate(int[] nums, int k) {
+        int n = nums.length;
+        k %= n;
+        int[] copyNums = new int[n];
+
+        int index = 0;
+        for (int i = n - k; i < n - k + n; i++) {
+            copyNums[index++] = nums[i % n];
+        }
+        for (int i = 0; i < n; i++) {
+            nums[i] = copyNums[i];
+        }
+    }
+}