tc srm 636 div2 500

100的数据直接暴力就行，想多了。。。

ac的代码：

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <vector>
#define LL __int64
const int maxn = 100+10;
using namespace std;
int a[maxn], sum;

class SortishDiv2
{
public:
    int ways(int sortedness, vector <int> seq)
    {
        int f[maxn], len, i, j, ans = 0;
        int cnt = 0, x[maxn];
        len = seq.size();
        memset(f, 0, sizeof(f));
        for(i = 0; i < len; i++)
            f[seq[i]] = 1;
        for(i = 1; i <= len; i++)
            if(f[i]==0)
                x[cnt++] = i;
        sort(x, x+cnt);
        do
        {
            int y = 0;
            for(i = 0; i < len; i++)
            {
                if(seq[i]==0) a[i] = x[y++];
                else a[i] = seq[i];
            }
            sum = 0;
            for(i = 0; i < len; i++)
            for(j = i+1; j < len; j++)
            if(a[j]>a[i])
            sum ++;
            if(sum == sortedness) ans ++;
        }
        while (next_permutation(x,x+cnt));  //数字的全排列

        return ans;
    }
};

/*int main()
{
    SortishDiv2 s;
    int i, j, n, y, tmp;
    vector<int>v;
    while(1)
    {
        v.clear();
        cin>>n; cin>>y;
        for(i = 0; i < y; i++)
        {
          cin>>tmp;
          v.push_back(tmp);
        }
        cout<<s.ways(n, v)<<endl;
    }
    return 0;
}*/