NYOJ 631 冬季长跑(逆序数＋单调递增序列个数)

#include <iostream>
#include <cstdio>
using namespace std;
#define N 1000000010
int sum,n,p[50001][21],len[50001],L[21],R[21];

void merger(int a[],int beg,int mid,int end)
{
    int L_len=mid-beg,R_len=end-mid-1;
    int i,j,k;
    for(i=0;i<=L_len;i++)
        L[i]=a[beg+i];
    for(j=0;j<=R_len;j++)
        R[j]=a[mid+j+1];
    L[L_len+1]=R[R_len+1]=N;
    i=j=0;
    for(k=beg;k<=end;k++)
    {
        if(L[i]<=R[j])
            a[k]=L[i++];
        else
        {
            a[k]=R[j++];
            sum+=L_len-i+1;
        }
    }
}

void mergerSort(int a[],int beg,int end)
{
    int mid=(beg+end)>>1;
    if(beg<end)
    {
        mergerSort(a,beg,mid);
        mergerSort(a,mid+1,end);
        merger(a,beg,mid,end);
    }
}

void slove(int k)
{
    int a = len[k]; len[k] = -1;
    for(int i = k+1; i < n; ++i)
    {
        if(len[i] != -1 && len[i] > a)
        {
            a = len[i]; len[i] = -1;
        }
    }
}

int main()
{
   // freopen("in.txt","r",stdin);
    int t,mi,i,j,ans;
    cin>>t;
    while(t--)
    {
        cin>>n;
        for(i=0;i<n;++i)
        {
            cin>>mi; sum = 0;
            for(j=0;j<mi;++j)
                cin>>p[i][j];
            mergerSort(p[i],0,mi-1);
            len[i] = sum;
        }
        ans = 0;
        for(i=0;i<n;++i)
        {
            if(len[i] != -1)
            {
                slove(i);
                ++ans;
            }
        }
        cout<<ans<<endl;
    }
    return 0;
}