(C++) 백준 10819번 차이를 최대로

#include <iostream>
using namespace std;

int arr[1001];
int D[1001];

int main(){

    int N;
    cin>>N;
    for (int i=0; i<N; i++) cin>>arr[i];

    int ans=0;

    for (int i=0; i<N; i++){
        D[i] = 1;
        for (int j=0; j<i; j++){
            int tmp=1;
            if (arr[j]<arr[i]) tmp=D[j]+1;
            D[i]=max(tmp, D[i]);
        }
        ans=max(ans, D[i]);
    }

    //for (int i=0; i<N; i++) cout<<D[i]<<" ";

    cout<<ans;
}