ZOJ 10th Anniversary Contest - G

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

char s1[200000],s2[200000],s3[200000],s4[200000];
long long a[200000],p[200000],q[200000],num[200000],v[200000];

int main()
{
    int t,n,m,i,j,k;
    scanf("%d",&t);
    while (t-->0)
    {
          scanf(" %s",s1);
          scanf(" %s",s2);
          n=strlen(s1);
          m=strlen(s2);
          long long ans=0;
          for (i=0; i<n; i++) {num[i]=0; a[i]=0; p[i]=0; q[i]=0;}
          p[0]=-1;
          s4[0]=s2[m-1];
          for (i=1; i<m; i++)
          {
              p[i]=-1;
              int k=p[i-1];
              while ((k>-1)&&(s2[k+1]!=s2[i])) k=p[k];
              if (k>-1) p[i]=k+1;
              if ((k==-1)&&(s2[0]==s2[i])) p[i]=0;
              s4[i]=s2[m-i-1];
         }
         int mark=-1;
         for (i=0; i<n; i++)
         {
             while (mark!=-1)
             {
                   if (s1[i]==s2[mark+1]) break;
                   mark=p[mark];      
             }
             if (mark!=-1) {mark++; num[mark]++;}
             else if (s1[i]==s2[0]) {mark=0; num[mark]++;}
             a[i]=mark;
             s3[i]=s1[n-i-1];
             if (mark==m-1) mark=p[mark];
         }
         q[0]=-1;
         for (i=1; i<m; i++)
          {
              q[i]=-1;
              int k=q[i-1];
              while ((k>-1)&&(s4[k+1]!=s4[i])) k=q[k];
              if ((k==-1)&&(s4[i]==s4[0])) q[i]=0;
              if (k>-1) q[i]=k+1;
         }         
         mark=-1;
         for (i=m-1; i>=0; i--)
             if (p[i]!=-1) num[p[i]]+=num[i];
         for (i=0; i<m; i++) 
         {
             v[i]=num[m-i-2];    
             if (q[i]!=-1) v[i]+=v[q[i]];
         }
         for (i=0; i<n; i++)
         {
             while (mark!=-1)
             {
                   if (s3[i]==s4[mark+1]) break;
                   mark=q[mark];      
             }
             if (mark!=-1) mark++;
             else if (s3[i]==s4[0]) mark=0;
             ans+=v[mark];
             if (mark==m-1) mark=q[mark];
         }                
         printf("%lld\n",ans);
          
    }    
    return 0;
}