> 我的想法是选找出各个框的左上角和右下角的顶点，然后选找出没有被覆盖的框(字母数与框上的点数一样)，将这个框的字母改为*，其他框再数一下有多少字母，框上的*也做字母算，如果这个字母数与框上的点数一样，这个框就是目前最上层的。重复这个过程直到找到结果。
> 
> #include <iostream>
> #include <algorithm>
> #include <math.h>
> #include <stdlib.h>
> #include <stdio.h>
> 
> using namespace std;
> 
> char a[32][32];
> int h, w;
> const int N = 5;
> const char STAR = '*';
> char list[] = {'A', 'B', 'C', 'D', 'E'};
> int total[] = {12, 14, 10, 18, 24};
> int x1__[N] = {-1, -1, -1, -1, -1};
> int y1__[N] = {-1, -1, -1, -1, -1};
> int x2__[N] = {-1, -1, -1, -1, -1};
> int y2__[N] = {-1, -1, -1, -1, -1};
> char result[N];
> int ri = 1;
> 
> 
> struct Node
> {
>     int index;
>     int differ;
> };
> 
> Node nodes[N];
> 
> bool less(Node n1, Node n2)
> {
>     return n1.differ < n2.differ;
> }
> 
> void findBorder()
> {
>     int i, j, index;
>     for(i=0; i<h; i++)
>     {
>         for(j=0; j<w; j++)
>         {
>             if(a[i][j]>='A' && a[i][j]<='E')
>             {
>                 index = a[i][j] - 'A';
>                 if(x1__[index]<0 || j<x1__[index])
>                     x1__[index] = j;
>                 if(y1__[index]<0 || i<y1__[index])
>                     y1__[index] = i;
>                 if(x2__[index]<0 || j>x2__[index])
>                     x2__[index] = j;
>                 if(y2__[index]<0 || i>y2__[index])
>                     y2__[index] = i;
>             }
>         }
>     }
> }
> 
> int countLetterAmount(int index)
> {
>     int i, k, count = 0;
>     char c = list[index];
> 
>     // top border
>     k = y1__[index];
>     for(i=x1__[index]; i<x2__[index]; i++)
>         if(a[k][i]==c || a[k][i]==STAR)
>             count++;
> 
>     // bottom border
>     k = y2__[index];
>     for(i=x1__[index]; i<x2__[index]; i++)
>         if(a[k][i]==c || a[k][i]==STAR)
>             count++;
> 
>     // left border
>     k = x1__[index];
>     for(i=y1__[index]+1; i<y2__[index]; i++)
>         if(a[i][k]==c || a[i][k]==STAR)
>             count++;
> 
>     // right border
>     k = x2__[index];
>     for(i=y1__[index]; i<=y2__[index]; i++)
>         if(a[i][k]==c || a[i][k]==STAR)
>             count++;
> 
>     return count;
> }
> 
> void fillStar(int index)
> {
>     int i, k, count = 0;
>     char c = list[index];
> 
>     // top border
>     k = y1__[index];
>     for(i=x1__[index]; i<x2__[index]; i++)
>         if(a[k][i]==c)
>             a[k][i] = STAR;
> 
>     // bottom border
>     k = y2__[index];
>     for(i=x1__[index]; i<x2__[index]; i++)
>         if(a[k][i]==c)
>             a[k][i]=STAR;
> 
>     // left border
>     k = x1__[index];
>     for(i=y1__[index]+1; i<y2__[index]; i++)
>         if(a[i][k]==c)
>             a[i][k]=STAR;
> 
>     // right border
>     k = x2__[index];
>     for(i=y1__[index]; i<=y2__[index]; i++)
>         if(a[i][k]==c)
>             a[i][k]=STAR;
> 
>     int j;
>     for(i=0; i<N; i++)
>     {
>         if(nodes[i].differ > 0)
>         {
>             j = nodes[i].index;
>             nodes[i].differ = total[j] - countLetterAmount(j);
>             //cout<<list[j]<<"\tdiffer:"<<nodes[i].differ<<"\tamount:"<<countLetterAmount(j)<<"\ttotal:"<<total[j]<<endl;
>         }
>     }
> }
> 
> void showAll()
> {
>     int i, j;
>     for(i=0; i<h; i++)
>     {
>         for(j=0; j<w; j++)
>             cout<<a[i][j];
>         cout<<endl;
>     }
> }
> 
> //void search(int ri)
> //{
> //    int i;
> //    if(ri < N)
> //    {
> //        for(i=1; i<N; i++)
> //        {
> //            if(nodes[i].differ == 0)
> //            {
> //                j = nodes[i].index;
> //                result[ri] = list[j];
> //                ri++;
> //                fillStar(j);
> //                showAll();
> //                nodes[i].differ--;
> //            }
> //        }
> //    }else
> //    {
> //        for(i=N-1; i>=0; i--)
> //            cout<<result[i];
> //        cout<<endl;
> //    }
> //}
> 
> int main()
> {
>     int i, j, count;
>     char str[256];
> 
>     cin.getline(str, 80);
>     h = atoi(str);
> 
>     while(h != 0)
>     {
>         cin.getline(str, 80);
>         w = atoi(str);
> 
>         for(i=0; i<h; i++)
>             cin>>a[i];;
> 
>         findBorder();
>         //showAll();
>         //for(i=0; i<N; i++)
>         //    cout<<list[i]<<"\t"<<x1__[i]<<","<<y1__[i]<<"\t"<<x2__[i]<<","<<y2__[i]<<endl;
> 
>         for(i=0; i<N; i++)
>         {
>             nodes[i].index = i;
>             nodes[i].differ = total[i] - countLetterAmount(i);
>             //cout<<list[nodes[i].index]<<"\t"<<nodes[i].differ<<endl;
>         }
>         sort(nodes, nodes+N, less);
>         //cout<<endl;
>         //for(i=0; i<N; i++)
>         //    cout<<list[nodes[i].index]<<"\t"<<nodes[i].differ<<endl;
> 
>         result[0] = list[nodes[0].index];
>         ri = 1;
>         fillStar(nodes[0].index);
>         //showAll();
> 
>         while(ri < N)
>         {
>             for(i=1; i<N; i++)
>             {
>                 if(nodes[i].differ == 0)
>                 {
>                     j = nodes[i].index;
>                     result[ri] = list[j];
>                     ri++;
>                     fillStar(j);
>                     //showAll();
>                     nodes[i].differ--;
>                 }
>             }
>         }
> 
>         for(i=N-1; i>=0; i--)
>             cout<<result[i];
>         cout<<endl;
>         getchar();
> 
>         cin.getline(str, 80);
>         h = atoi(str);
>     }
> 
>     return 0;
> }