[codevs4748]低价购买

题目←

大意：

求最长不上升子序列及方案数

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<map>
#define INF 1061109567
using namespace std;
const int MAXN = 5000 + 50;
int f[MAXN],g[MAXN],h[MAXN],n;
int ans,sum;
map <int,bool> vis;
int main()
{
    scanf("%d",&n);
    for(int i = 1;i <= n;i ++)
    {
        scanf("%d",&h[i]);
    }
    h[++ n] = -INF;
    for(int i = 1;i <= n;i ++)
    {
        f[i] = 1;
        for(int j = 1;j < i;j ++)
        if(h[j] > h[i])
        {
            f[i] = max(f[i],f[j] + 1);
        }
        ans = max(ans,f[i]);
    }
    g[1] = 1;
    for(int i = 1;i <= n;i ++)
    {
        vis.erase(vis.begin(),vis.end());
        for(int j = i - 1;j >= 1;j --)
        {
            if(h[j] > h[i] && f[j] == f[i] - 1)
            {
                //if(i == 10)printf("%d\n",j);
                if(vis[h[j]])continue;
                g[i] += g[j];
                vis[h[j]] = true;
            }
        }
        if(!g[i])g[i] = 1;
    }
    printf("%d %d",ans - 1,g[n]);
    return 0;
}

题解在Loi_lxt 的博客里写的很清楚了