feat: solved 300

Author: fghpdf

src/com/fghpdf/LongestIncreasingSubsequence/Solution.java

@@ -0,0 +1,36 @@
+package com.fghpdf.LongestIncreasingSubsequence;
+
+/**
+ * @author fghpdf
+ * @date 2019/12/26
+ * https://leetcode.com/problems/longest-increasing-subsequence/
+ * https://leetcode.com/problems/longest-increasing-subsequence/discuss/74824/JavaPython-Binary-search-O(nlogn)-time-with-explanation
+ * len = 1   :      [4], [5], [6], [3]   => tails[0] = 3
+ * len = 2   :      [4, 5], [5, 6]       => tails[1] = 5
+ * len = 3   :      [4, 5, 6]            => tails[2] = 6
+ * (1) if x is larger than all tails, append it, increase the size by 1
+ * (2) if tails[i-1] < x <= tails[i], update tails[i]
+ **/
+public class Solution {
+	public int lengthOfLIS(int[] nums) {
+		int[] tails = new int[nums.length];
+		int size = 0;
+		for (int x : nums) {
+			int i = 0;
+			int j = size;
+			while (i != j) {
+				int middle = (i + j) / 2;
+				if (tails[middle] < x) {
+					i = middle + 1;
+				} else {
+					j = middle;
+				}
+			}
+			tails[i] = x;
+			if (i == size) {
+				size++;
+			}
+		}
+		return size;
+	}
+}