feat: solved 324

Author: fghpdf

src/com/fghpdf/WiggleSortII/Solution.java

@@ -0,0 +1,54 @@
+package com.fghpdf.WiggleSortII;
+
+import java.util.Arrays;
+import java.util.Comparator;
+
+/**
+ * @author fghpdf
+ * @date 2019/12/29
+ * https://leetcode.com/problems/wiggle-sort-ii/
+ * 没懂。。。
+ * https://leetcode.com/problems/wiggle-sort-ii/discuss/77682/Step-by-step-explanation-of-index-mapping-in-Java
+ **/
+public class Solution {
+	public void wiggleSort(int[] nums) {
+		int median=findKthLargest(nums,(nums.length+1)/2);
+		int odd=1;
+		int even=nums.length%2==0?nums.length-2:nums.length-1;
+		int[] tmpArr=new int[nums.length];
+		for(int i=0;i<nums.length;i++){
+			if(nums[i]>median){
+				tmpArr[odd]=nums[i];
+				odd+=2;
+				continue;
+			}
+			if(nums[i]<median){
+				tmpArr[even]=nums[i];
+				even-=2;
+				continue;
+			}
+		}
+		while(odd<nums.length){
+			tmpArr[odd]=median;
+			odd+=2;
+		}
+		while(even>=0){
+			tmpArr[even]=median;
+			even-=2;
+		}
+		for(int i=0;i<nums.length;i++){
+			nums[i]=tmpArr[i];
+		}
+
+
+	}
+
+	private int findKthLargest(int[] nums, int k) {
+		int[] sorted = Arrays.stream(nums).boxed()
+				.sorted(Comparator.reverseOrder())
+				.mapToInt(Integer::intValue)
+				.toArray();
+
+		return sorted[k - 1];
+	}
+}