Lưu ý: Các code mẫu dưới đây chỉ mang tính tham khảo và có thể không AC được bài tập này

Code mẫu của RR

//Written by Nguyen Thanh Trung
{$R+,Q+}
{$Mode objFPC}
uses math;
const
  FINP='';
  FOUT='';
  MAXN=101;
type
  big=array[0..MAXN] of longint;
operator + (a,b:big) c:big;
var
  i,nho:longint;
begin
  fillchar(c,sizeof(c),0);
  c[0]:=max(a[0],b[0]); nho:=0;
  for i:=1 to c[0] do
    begin
      c[i]:=a[i]+b[i]+nho;
      if c[i]<100 then nho:=0
      else begin nho:=1; c[i]-=100; end;
    end;
  if nho>0 then begin inc(c[0]); c[c[0]]:=nho; end;
end;
operator * (a:big; k:longint) c:big;
var
  i,nho:longint;
begin
  fillchar(c,sizeof(c),0);
  c[0]:=a[0]; nho:=0;
  for i:=1 to c[0] do
    begin
      c[i]:=a[i]*k+nho;
      if c[i]<100 then nho:=0
      else begin nho:=c[i] div 100; c[i]:=c[i] mod 100; end;
    end;
  if nho>0 then
    begin
      inc(c[0]);
      c[c[0]]:=nho;
    end;
end;
var
  f1,f2:text;
procedure print(var a:big); inline;
var
  i:longint;
begin
  while (a[0]>0) and (a[a[0]]=0) do dec(a[0]);
  if a[0]=0 then
    begin
      writeln(f2,0);
      exit;
    end;
  for i:=a[0] downto 1 do
    if (a[i]<10) and (i<a[0]) then write(f2,'0',a[i])
    else write(f2,a[i]);
  writeln(f2);
end;
var
  n:longint;
  val:array[char] of longint;
  lt:array[1..MAXN,0..MAXN] of big;
  s:string;
procedure openF;
begin
  assign(f1,FINP); reset(f1);
  assign(f2,FOUT); rewrite(f2);
end;
procedure closeF;
begin
  close(f1);
  close(f2);
end;
procedure init;
var
  base,i:longint;
begin
  for base:=1 to 99 do
    begin
      lt[base,0][0]:=1; lt[base,0][1]:=1;
      for i:=1 to MAXN do
        lt[base,i]:=lt[base,i-1]*base;
    end;
end;
procedure input(var s:string;k:boolean);
begin
  if k then
    repeat
      readln(f1,s);
      while s[1]=' ' do delete(s,1,1);
      while s[length(s)]=' ' do delete(s,length(s),1);
      if s='' then continue;
      while ord(s[1])<21 do delete(s,1,1);
      while ord(s[length(s)])<21 do delete(s,length(s),1);
    until s<>''
  else
    begin
      readln(f1,s);
      while s[1]=' ' do delete(s,1,1);
      while s[length(s)]=' ' do delete(s,length(s),1);
      if s='' then exit;
      while ord(s[1])<21 do delete(s,1,1);
      while ord(s[length(s)])<21 do delete(s,length(s),1);
    end;
end;
var
  kq,sum:big;
  a:string;
procedure solve;
var
  i,maxbase,base,ln,now:longint;
begin
  maxbase:=n;
  repeat
    input(a,false);
    if a='' then continue;
    ln:=0;
    for i:=1 to length(a) do
      ln:=max(ln,val[a[i]]);
    fillchar(sum,sizeof(sum),0);
    for base:=ln+1 to maxbase do
      begin
        fillchar(kq,sizeof(kq),0); now:=0;
        for i:=length(a) downto 1 do
          begin
            kq+=lt[base,now]*val[a[i]];
            inc(now);
          end;
        sum+=kq;
      end;
    print(sum);
  until a='';
  if not eof(f1) then writeln(f2);
end;
begin
  init;
  openF;
  while not eof(f1) do
    begin
      input(s,true); n:=length(s);
      for n:=1 to n do
        val[s[n]]:=n-1;
      solve;
    end;
  closeF;
end.

Code mẫu của hieult

#include <cstdio>
#include <stdio.h>
#include <cstring>
//#include <conio.h>
#define bigbase 10000000
#define biglen 250

void big_intadd(int target[], int n)
{
     int i;
     for( i = 1;n;i++)
     {
         if(i<=target[0]) n+= target[i];
         target[i] = n%bigbase;
         n/=bigbase;
     }
     if(i-1>target[0]) target[0] = i-1;
 }

void big_addto(int target[],int source[])
{
     int carry = 0,i;
     for(i = 1;(i<=target[0])|| (i<=source[0])||carry;i++)
     {
         if(i<=target[0]) carry+=target[i];
         if(i<=source[0]) carry+=source[i];
         target[i] = carry%bigbase;
         carry/= bigbase;

     }
     if(i-1>target[0]) target[0] = i-1;
}

void big_intmul(int target[],int n)
{
     int carry = 0,i;
     for(i = 1;(i<=target[0])||carry;i++)
     {
            //printf("%d ",target[0]);
           if(i<=target[0]) carry+=n*target[i];
           target[i] = carry%bigbase;
           carry/=bigbase;
     }
     if(i-1>target[0]) target[0] = i-1;
}
void big_print(int source[])
{
      int i;
      printf("%d",source[source[0]]);
      for(i=source[0]-1;i>0;i--) printf("%07d",source[i]);
      printf("\n");
}

 #define numlen 22222
 char line[numlen];

int read_line(void)
{
    int i,j;
    if(fgets(line,sizeof(line),stdin)==NULL) return -1;
    for(i=j=0;line[i];i++) if(line[i]>32) line[j++] = line[i];
    line[j] = '\0';
    return j;
}

int digitvalue[128];
int maxbase;

void find_conversion(int len)
{
     int i;
     for(int i = 0;i<len;i++) digitvalue[line[i]] = i;
     maxbase = len;
}

int digit[numlen];
int minbase;

void convert_line(int len)
{
     int i;
     minbase = 2;
     for(i = 0;i<len;i++)
     {
           digit[i] = digitvalue[line[i]];
           if(digit[i]>=minbase) minbase = digit[i]+1;
     }
}

void to_bignum(int target[],int base,int len)
{
     int i;
     target[0] = 0;
     for(i = 0;i<len;i++)
     {
           big_intmul(target,base);
           big_intadd(target,digit[i]);
     }
}

int main()
{
    //freopen("MCONVERT.in","r",stdin);
    int len,cases =0,base,sum[biglen],number[biglen];
    while((len = read_line())>=0)
    {
        if(len == 0) continue;
        if(cases++) printf("\n");
        find_conversion(len);
        while((len=read_line())>0)
        {
            convert_line(len);
            sum[0] = 0;
            for(base = minbase;base<=maxbase;base++)
            {
                to_bignum(number,base,len);
                big_addto(sum,number);
            }
            big_print(sum);
        }
        if(len<0) break;
    }
   // getch();
}