26. （阅读程序写结果）

#include<iostream>
#include<string>
using namespace std;
int lefts[20],rights[20],father[20];
string s1,s2,s3;
int n,ans;

void calc(int x,int dep)
{
  ans=ans+dep*(s1[x]-'A'+1);
  if(lefts[x]>=0)calc(lefts[x],dep+1);
  if(rights[x]>=0)calc(rights[x],dep+1);
}

void check(int x)
{
  if(lefts[x]>=0)check(lefts[x]);
  s3=s3+s1[x];
  if(rights[x]>=0)check(rights[x]);
}

void dfs(int x,int th)
{
  if(th==n)
  {
    s3="";
    check(0);
    if(s3==s2)
    {
      ans=0;
      calc(0,1);
      cout<<ans<<endl;
    }
    return;
  }
  if(lefts[x]==-1&&rights[x]==-1)
  {
    lefts[x]=th;
    father[th]=x;
    dfs(th,th+1);
    father[th]=-1;
    lefts[x]=-1;
  }
  if(rights[x]==-1)
  {
    rights[x]=th;
    father[th]=x;
    dfs(th,th+1);
    father[th]=-1;
    rights[x]=-1;
  }
  if(father[x]>=0)
    dfs(father[x],th);
}

int main()
{
  cin>>s1;
  cin>>s2;
  n=s1.size(s1)
  memset(lefts,-1,sizeof(lefts));
  memset(rights,-1,sizeof(rights));
  memset(father,-1,sizeof(father));
  dfs(0,1);
}

输入：

ABCDEF

BCAEDF

输出：{{ input(1) }}