Hdu 1063 Exponentiation

模拟高精度题。这题也真是。。。无语了。

CODE:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
using namespace std;
#define END -1
const int maxn = 1001;
int BigNumber[maxn] = {0};

void multiple(int a[], int n)         //大整数相乘 
{
    int i, j;
    int c = 0; //进位 
    for(i = 1; i <= a[0]; i++)
    {
        a[i] = a[i]*n + c;
        c = a[i]/10;
        a[i] %= 10;
    }
    while(c)
    {
        a[i++] = c%10;
        c /= 10;
    }
    a[0] = i-1;
    return ;
}


void output(int pos)
{
    int i, j;
    if(BigNumber[0] > pos)         //有整数 
    {
        for(j = 0, i = BigNumber[0]; j < BigNumber[0] - pos ; j++, i--)         //输出小数点前的数字 
        {
            printf("%d", BigNumber[i]);
        }
        for(j = 1 ; BigNumber[j] == 0; j++) BigNumber[j] = END;  //    去零 
        if(BigNumber[i] == END || i == 0) return;       //整数的话 
            printf(".");
        for(; BigNumber[i] != END && i >= 1 ; i--)            //输出小数点后的数字 
         printf("%d", BigNumber[i]);
    }
    else         //无整数 
    {
        printf(".");
        for(i = 0 ; i < pos - BigNumber[0]; i++)                 
            printf("0");
        for(j = 1; BigNumber[j] == 0; j++) BigNumber[j] = END;    //去零 
         for(i = BigNumber[0]; BigNumber[i] != END && i >= 1; i--)      
           printf("%d", BigNumber[i]);
    }
    return ;
}


int main()
{
    char s[10];
    int n;
    int pos, num;
    while(~scanf("%s%d", s, &n))
    {
        int i, j;
        int l = strlen(s);
        num = 0;
        memset(BigNumber, 0 ,sizeof(BigNumber));
        for(i = 0, pos = 5; i < l ; i++)                  //pos = 5,万一没有小数点，则pos = 5;
        {
            if(s[i] == '.') pos = i;
            else num = num*10 + s[i]-'0';             //将小数转换为整数。 
        }
        BigNumber[0] = BigNumber[1] = 1;
        pos = (5-pos)*n;                      //一共有几位小数 
        while(n--)
        {
            multiple(BigNumber, num);       //大数相乘 
        }
        output(pos);       //输出 
        printf("\n");
    }
    return 0;

}