update

hard/321.create-maximum-number.java

@@ -0,0 +1,36 @@
+class Solution {
+    public int[] maxNumber(int[] nums1, int[] nums2, int k) {
+        int[] res = new int[0];
+        for (int i = Math.max(0, k - nums2.length); i <= Math.min(k, nums1.length); i++) {
+            res = max(res, 0, merge(pick(nums1, i), pick(nums2, k - i)), 0);
+        }
+        return res;
+    }
+
+    private int[] max(int[] nums1, int i1, int[] nums2, int i2) {
+        for (int i = i1; i < nums1.length; i++) {
+            int j = i2 + i - i1;
+            if (nums2.length <= j) return nums1;
+            if (nums1[i] < nums2[j]) return nums2;
+            if (nums2[j] < nums1[i]) return nums1;
+        }
+        return nums2;
+    }
+
+    private int[] pick(int[] nums, int k) {
+        int[] res = new int[k];
+        int j = 0;
+        for (int i = 0; i < nums.length; i++) {
+            while (0 < j && res[j - 1] < nums[i] && k <= (nums.length - i + j - 1)) j--;
+            if (j < k) res[j++] = nums[i];
+        }
+        return res;
+    }
+
+    private int[] merge(int[] nums1, int[] nums2) {
+        int[] res = new int[nums1.length + nums2.length];
+        for (int i = 0, j = 0, k = 0; k < res.length; k++)
+            res[k] = max(nums1, i, nums2, j) == nums1 ? nums1[i++] : nums2[j++];
+        return res;
+    }
+}