up sequence 더블릿 (LIS)

#include <stdio.h>
#include <algorithm>
 
using namespace std;
 
int arr[10005] = { 0 };
int dp[10005] = { 0 };
int par[10005] = { 0 };
 
void printPar(int x) {
    if (x == 0) return;
 
    printPar(par[x]);
    printf("%d ", arr[x]);
}
 
int main() {
    int n;
    scanf("%d", &n);
 
    for (int i = 1; i <= n; i++) {
        scanf("%d", &arr[i]);
    }
    dp[1] = 1;
 
    for (int i = 2; i <= n; i++) {
        int maxNum = 0;
        for (int j = 1; j < i; j++) {
            if (arr[j] < arr[i]) {
                if (maxNum <= dp[j]) {
                    par[i] = j;
                    maxNum = dp[j];
                }
            }
        }
        dp[i] = maxNum + 1;
    }
    
    int maxNum = 0,x;
    for (int i = 1; i <= n; i++) {
        if (maxNum <= dp[i]) {
            x = i;
            maxNum = dp[i];
        }
    }
    printf("%d\n",maxNum);
    printPar(x);
}