經典題，不解釋，可以看我之前文章。

普通dp

public class Solution {public int lengthOfLIS(int[] nums) {if (nums.length == 0) {return 0;}int[] dp = new int[nums.length];dp[0] = 1;int maxans = 1;for (int i = 1; i < dp.length; i++) {int maxval = 0;for (int j = 0; j < i; j++) {if (nums[i] > nums[j]) {maxval = Math.max(maxval, dp[j]);}}dp[i] = maxval + 1;maxans = Math.max(maxans, dp[i]);}return maxans;}
}

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二分dp

public class Solution {public int lengthOfLIS(int[] nums) {int[] dp = new int[nums.length];int len = 0;for (int num : nums) {int i = Arrays.binarySearch(dp, 0, len, num);if (i < 0) {i = -(i + 1);}dp[i] = num;if (i == len) {len++;}}return len;}
}