OpenJudge Bailian 2757 最长上升子序列 DP

#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <queue>
#include <vector>
#include <iomanip>
#include <math.h>
#include <map>
using namespace std;
#define FIN     freopen("input.txt","r",stdin);
#define FOUT    freopen("output.txt","w",stdout);
#define INF     0x3f3f3f3f
#define INFLL   0x3f3f3f3f3f3f3f
#define lson    l,m,rt<<1
#define rson    m+1,r,rt<<1|1
typedef long long LL;
typedef pair<int,int> PII;

int a[1005];
int dp[1005];

int main()
{
    //FIN
    int n;
    scanf("%d", &n);
    int m;
    dp[1] = 1;
    for(int i = 1; i <= n; i ++)
        scanf("%d", &a[i]);
    for(int i = 2; i <= n;i ++){
        m = 0;
        for(int j = 1; j <= i-1; j ++){
            if(a[j] < a[i] && dp[j] > m){  //在前i-1中，找出终点小于dp[i]的最长的子序列
                m = dp[j];
            }
        }
        dp[i] = m + 1;
    }
    sort(dp + 1, dp +1 +n);
    printf("%d", dp[n]);

}