UVALive 6508 Permutation Graphs

Permutation Graphs

Time Limit:3000MS     Memory Limit:0KB     64bit IO Format:%lld & %llu

Submit Status Practice UVALive 6508

 #include<stdio.h>
 #include<string.h>

 int temp[],a[],b[],c[],b1[];
 long long num;

 void merg_sort(int a[],int l,int r)
 {
     int  i,j,len=r-l,p1,p2;
     if(len<=)
         return;
     int mid=l+len/;
     merg_sort(a,l,mid);
     merg_sort(a,mid,r);
     p1=l,p2=mid;
     for(i=l;i<r;i++)
     {
         if(p1==mid)
         {
             temp[i]=a[p2];
             p2++;
         }
         else if(p2==r)
         {
             temp[i]=a[p1];
             p1++;
         }
         else
         {
             if(a[p1]<=a[p2])
             {
                 temp[i]=a[p1];
                 p1++;
             }
             else
             {
                 temp[i]=a[p2];
                 p2++;
                 num=num+mid-p1;
             }
         }
     }
     for(i=l;i<r;i++)
         a[i]=temp[i];
     return;
 }

 int main()
 {
     int T;
     int n,i,j,k;
     scanf("%d",&T);
     while(T--)
     {
         num=;
         scanf("%d",&n);
         for(i=;i<=n;i++)
             scanf("%d",&b[i]);
         for(i=;i<=n;i++)
             b1[b[i]]=i;

         for(i=;i<=n;i++)
             scanf("%d",&c[i]);
         for(i=;i<=n;i++)
             a[i]=b1[c[i]];

         /*for(i=1;i<=n;i++)
             printf("%d ",a[i]);*/
         merg_sort(a,,n+);
         printf("%lld\n",num);
     }
     return ;
 }