mycode/code_study/Baekjoon/java/_12015.java

import java.util.*;

public class _12015 {
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        int[] A = new int[N];
        for(int i=0; i<N; i++) A[i] = sc.nextInt();

        sc.close();

        int[] LIS = new int[N];
        int len = 0;
        LIS[len++] = A[0];

        for(int i=1; i<N; i++) {
            int num = A[i];

            if(LIS[len-1] < num) LIS[len++] = num;
            else {
                int left = 0, right = len-1;
                int mid = (left + right) / 2;
                while(left < right) {
                    if(LIS[mid] < num) left = mid + 1;
                    else right = mid;

                    mid = (left + right) / 2;
                }

                LIS[mid] = num;
            }
        }

        System.out.println(len);
    }
}