poj 2533 Longest Ordered Subsequence(dp)

题意：给出一序列，求出该序列的最长上升子序列的最大长度。

#include <iostream>
#include <cstdio>
using namespace std;

#define MAX(a,b) a>b?a:b
int a[1005], dp[1005], n;

int DP()
{
    int i, j;

    for (i = 1; i <= n; i++)
    {
        dp[i] = 1;
        for (j = 1; j < i; j++)
        {
            if (a[i] > a[j])
                dp[i] = MAX (dp[i], dp[j] + 1);
        }
    }
    int ans = 0;
    for (i = 1; i <= n; i++)
        if (dp[i] > ans) ans = dp[i];
    return ans;
}

int main()
{
    scanf ("%d", &n);
    if (n == 0)
    {
        printf ("1\n");
        return 0;
    }
    for (int i = 1; i <= n; i++)
        scanf ("%d", &a[i]);
    printf ("%d\n",DP());
    return 0;
}