题解 | #最长上升子序列(一)#

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.StreamTokenizer;
import java.util.Arrays;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br  = new BufferedReader(new InputStreamReader(System.in));
        StreamTokenizer st  = new StreamTokenizer(br);
        st.nextToken();
        int n = (int)st.nval;
        if (n == 0) {
            System.out.println(0);
        } else if (n == 1) {
            System.out.println(1);
        } else {
            long[] arr = new long[n];
            for (int i = 0; i < n; i++) {
                st.nextToken();
                arr[i] = (long)st.nval;
            }
            int subMaxLen = 0;
            int[] len = new int[n];
            Arrays.fill(len, 1);
            for (int i = 1; i < n; i++) {
                for (int j = 0; j < i; j++) {
                    if (arr[i] > arr[j]) {
                        len[i] = Math.max(len[i], len[j] + 1);
                    }
                }
                subMaxLen = Math.max(subMaxLen, len[i]);
            }
            System.out.println(subMaxLen);
        }
    }


}