map和字符型数组的问题

#include <cstring>
#include <vector>
#include <algorithm>
using namespace std;

struct foo_item
{
    char english[11];
    unsigned long long martian; // 将字符串转换为数值比较的话，速度肯定比strcmp快多了

    foo_item( const char eng[11], const char mar[11] )
    {
        memcpy( english, eng, sizeof(english) );

        martian = 0;
        for( const char* p=mar; *p; ++p )
            martian = martian*26 + (*p-'a');
    }

    bool operator< ( const foo_item& rhs ) const
    {
        return martian < rhs.martian;
    }
};

struct foo
{
    std::vector<foo_item> english_martian;

    foo( size_t reserve_size )
    {
        english_martian.reserve( reserve_size );
    }
    void insert( const char eng[11], const char mar[11] )
    {
        english_martian.push_back( foo_item(eng,mar) );
    }
    void sort()
    {
        std::sort( english_martian.begin(), english_martian.end() );
    }
    const char* find( const char* mar_begin, const char* mar_end ) const
    {
        if( mar_end-mar_begin > 10 )
            return NULL;

        foo_item tmp( "", "" );
        tmp.martian = 0;
        for( const char* p=mar_begin; p!=mar_end; ++p )
            tmp.martian = tmp.martian*26 + (*p-'a');

        std::vector<foo_item>::const_iterator itor = std::lower_bound( english_martian.begin(), english_martian.end(), tmp );
        if( itor==english_martian.end() || tmp<*itor )
            return NULL;

        return itor->english;
    }
};

int main()
{
    // 读入字典表
    foo f( 1000 ); // 1000是瞎猜的，文中没提到字典大约有多少行。设正确了能提高效率，但不设也没关系
    {
        scanf( "%*s" ); // 忽略起始的START
        for( char english[11], martian[11]; scanf("%s%s",english,martian), english[0]!='E'; )
            f.insert( english, martian );
        f.sort();
    }

    // 读取martian文，并翻译
    scanf( "%*c" ); // 忽略
    for( char line[3001]; fgets(line,3000,stdin), strcmp(line,"END\n")!=0; )
    {
        for( const char* p=line; *p; )
        {
            if( *p<'a' || *p>'z' )
            {
                putchar( *p );
                ++p;
                continue;
            }

            const char* p1 = p;
            for( ++p; *p && *p>='a' && *p<='z'; ++p );

            const char* str = f.find( p1, p );
            if( str )
                printf( "%s", str );
            else
                printf( "%.*s", size_t(p-p1), p1 );
        }
    }

    return 0;
}