POJ 1952-最长下降子序列+去重

题目链接

#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <string>
#include <string.h>
#include <cmath>
#include <sstream>
#include <set>
#include <map>
#include <functional>
#include <queue>
#include <vector>
using namespace std;

const int maxn = 5010;
int arr[maxn], dp[maxn], nums[maxn];
int n;

int main()
{
cin >> n;
for (int i = 0; i < n; i++)
{
cin >> arr[i];
dp[i] = 1;
nums[i] = 1;
}

for (int i = 1; i < n; i++)
{
for (int j = i - 1; j >= 0; j--)
{
if (arr[i] < arr[j])
{
if (dp[i] < dp[j] + 1)
{
dp[i] = dp[j] + 1;
nums[i] = nums[j];
}
else if (dp[i] == dp[j] + 1)
{
nums[i] += nums[j];
}
}
else if (arr[i] == arr[j])
{
if (dp[i] == 1)
nums[i] = 0;
break;
}
}
}
int len = 0, times = 0;
for (int i = 0; i < n; i++)
{
len = max(dp[i], len);
}
for (int i = 0; i < n; i++)
{
if (dp[i] == len)
times += nums[i];
}
cout << len << " " << times << endl;
//system("pause");
}