var 
   a: array[0..9] of word; 
   j, n, i, num, s, min, h: integer; 
 begin 
   readln(n); 
  
   for i:=0 to 9 do a[i ]:=0; 
  
   for i := 1 to n do begin 
     readln(num); 
     while num > 0 do  begin 
        s:= num mod 10; 
        a[s ] := a[s ] + 1; 
        num := num div 10; 
     end 
   end; 
  
   for i := 0 to 9 do 
     if a[i ] <> 0 then begin 
       s:= i; break;  
     end; 
   for i := s to 9 do begin 
     min:= s; 
     while (a[min] = 0) and (min < 9) do 
       min:= min + 1; 
     if a[min] = 0 then break; 
     for j:= min to 9 do 
        if (a[j]<>0) and (a[j] < a[min]) then min:=j; 
     for h:= 9 downto s do 
       if (a[min] = a[h]) and (a[h] <> 0) then begin 
          write(h, ' ');  
          a[h]:= 0;  
       end;    
   end; 
 end. 
 

 
     int max2, max1 = -1; 
     do { 
         max2 = max1; 
         max1 = 0; 
         for (int j=0; j<10; j++) { 
             if (a[j] > max1) max1 = a[j]; 
             if (a[j] == max2) { 
                 cout << j << " "; 
                 a[j] = 0; 
             } 
         } 
     } while (max1>0); 
 

var s: string[4]; 
   ... 
 begin 
   readln(n); 
   {Инициализация массива счетчиков} 
   .... 
    for j:=1 to n do begin 
      Readln(s); 
      for k:= 1 to length(s) do 
        inc(a[ord(s[k])-ord('0')]); 
    end; 
    ... 
 

 
 #include <string> 
 #include <iostream> 
 using namespace std; 
  
 int main() { 
   string s; 
   cin >> s; // Ввели строку 
   for (int j=0; j<s.size(); j++) cout << s[j]; // Вывели посимвольно 
   return 0; 
 }

const 
   N = 100000; 
 var 
   a: array[0..9] of integer; 
   f: textfile; 
   i, x, k: integer; 
   s: string[5]; 
 begin 
   assign(f, 'test.txt'); 
   rewrite(f); 
   for i:= 1 to N do 
     writeln(f, random(30000)); 
   close(f); 
   {Вариант А} 
   for k:= 0 to 9 do a[k]:= 0; 
   reset(f); 
   var d := Milliseconds; 
   for i:= 1 to N do begin 
     readln(f, x); 
     while x > 0 do begin 
       inc(a[x mod 10]); 
       x:= x div 10 
     end; 
   end; 
   close(f); 
   writeln((Milliseconds-d)/1000); 
   {Вариант Б} 
   for k:= 0 to 9 do a[k]:= 0; 
   reset(f); 
   d := Milliseconds; 
   k:= ord('0'); 
   for i:= 1 to N do begin 
     readln(f, s); 
     for x:= 1 to length(s) do 
       inc(a[ord(s[x])-k]); 
   end; 
   close(f); 
   writeln((Milliseconds-d)/1000); 
 end.

 
 вариант А: 0.039 
 вариант Б: 0.046 
 

 
 вариант А: 0.039 
 вариант Б: 0.015 
 

	int min2, min1 = -1; 
 	do { 
 		min2 = min1; 
 		min1 = 0; 
 		for (int j=9; j>=0; j--) { 
 			if (a[j] > 0 && (a[j] < min1 || min1<=0)) min1 = a[j];  
 			if (a[j] == min2) { 
 				cout << j << " "; 
 				a[j] = 0; 
 			} 
 		} 
 	} while (min1>0);

struct dic { 
   char key; // ключ, то есть символы '0'..'9' 
   int val;  // счётчик 
 };