题解 | #最长上升子序列(一)#
最长上升子序列(一)
https://www.nowcoder.com/practice/5f65ccbb025240bd8458eb6479c2612e
import java.util.Arrays;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int n = in.nextInt();
int[] dp = new int[n];
int[] a = new int[n];
for(int i = 0; i < n; i++)a[i] = in.nextInt();
Arrays.fill(dp, 1);
int maxLen = 1;
for(int i = 1; i < n; i++) {
for(int j = 0; j < i; j++) {
if(a[j] < a[i])dp[i] = Math.max(dp[i], dp[j] + 1);
}
maxLen = Math.max(maxLen, dp[i]);
}
System.out.println(maxLen);
}
}
一维dp，但是时间复杂度为O(n^2)，因为是求子序列，所以要和当前数的前面的所有数进行比较
