高精度进位制转换，Poj(1220)

转自ACdream。

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define MAXSIZE 60000

char in[MAXSIZE];
int oldbase,newbase;
int a[MAXSIZE],b[MAXSIZE],r[MAXSIZE];

int getNum(char c)
{
    if(c >= '0' && c <= '9') return c - '0';
    if(c >= 'A' && c<= 'Z' ) return c - 'A' + 10;
    return c - 'a' + 36;
}

char getChar(int i)
{
    if(i >= 0 && i <= 9) return i + '0';
    if(i >= 10 && i <= 35) return i - 10 + 'A';
    return i - 36 + 'a';
}

void chToNum()
{
    a[0] = strlen(in);
    for(int i=1;i<=a[0];i++)
    {
        a[i] = getNum(in[i-1]);
    }
}

void alter()
{
    while(a[0] >= 1)
    {
        int i,t = 0;
        for(i=1;i<=a[0];i++)
        {
            t = t * oldbase + a[i];
            b[ ++b[0] ] = t / newbase;
            t %= newbase;
        }
        r[ ++r[0] ] = t;
        b[0] = a[0];
        for(i = 1; i <= b[0] && !b[i]; i++) ;
        for(a[0] = 0; i <= b[0]; i++) a[ ++a[0] ] = b[i];
        memset(b,0,sizeof(b));
    }
}

void print()
{
    printf("%d %s
%d ",oldbase,in,newbase);
    while(r[0]>=1)
    {
        printf("%c",getChar(r[ r[0]-- ]));
    }
    printf("

");
}

int main()
{
    int n;
    while(scanf("%d",&n)!=EOF)
    {
        while(n--)
        {
            scanf("%d %d %s",&oldbase,&newbase,in);
            chToNum();
            alter();
            print();
        }
    }
    return 0;
}