高手看过来,帮该个程序, - C语言论坛

问题点数：0 回复次数：6

高手看过来,帮该个程序,

#include "stdio.h"

int main(void)
{
char binaryNum[100]="101011.01011110011101";
char *p = binaryNum;
float  decimalNum = 0;
int  n = 0, dotsNum = 0, i = 0, j = 0;
for ( ; *p != '\0'; p++, n++) {
if (! (*p == '0' || *p == '1' || *p == '.')) {
printf("bad input!\n");
return 1;
}
if (*p == '.') {
dotsNum++;
if (dotsNum == 1)
i = n;
else {
printf("bad binary number!\n");
return 1;
}
}
}
if (dotsNum)
j = n -1 - i;
else
i = n;

p = binaryNum;

for ( ; i > 0; p++, i--)
if (*p == '1')
decimalNum += pow(2, i -1);
for (p++, i = 1; i <= j; p++, i++)
if (*p == '1')
decimalNum += pow(2, -i);

printf("The converted decimal number is:\n");
printf("%f\n", decimalNum);

return 0;

}
float pow (int m,int n)
{float sum=1;

int i;
if (n>0)
{for (i=1;i<=n;i++)
    sum=m*sum;
    }
    else
{if(n==0)
    sum=1;
    else{
if(n<0)
{for (i=1;i<=(-n);i++)
    sum=sum*(1/m);

}
}
}
return(sum);
}该程序是计算二进制浮点数转化成十进制,不用<MATH.H>涵数,二采用调用(幂),理论结果为方43.23645,可是该程序运行后是43.00000,小数部分没了,该怎样该啊,急急啊,急的不行了.

搜索更多相关主题的帖子: dotsNum　binaryNum　

第 2 楼

得分:0

/********************************************************
** Highlight software by yzfy(雨中飞燕) http:// *
*********************************************************/
#include "stdio.h"

int main(void)
{
    char binaryNum[100]="101011.01011110011101";
    char *p = binaryNum;
    float  decimalNum = 0;
    int  n = 0, dotsNum = 0, i = 0, j = 0;
    for ( ; *p != '\0'; p++, n++)
    {
        if (! (*p == '0' || *p == '1' || *p == '.'))
        {
            printf("bad input!\n");
            return 1;
        }
        if (*p == '.')
        {
            dotsNum++;
            if (dotsNum == 1)
                i = n;
            else
            {
                printf("bad binary number!\n");
                return 1;
            }
        }
    }
    if (dotsNum)
        j = n -1 - i;
    else
        i = n;

    p = binaryNum;

    for ( ; i > 0; p++, i--)
        if (*p == '1')
            decimalNum += pow(2, i -1);
    for (p++, i = 1; i <= j; p++, i++)
        if (*p == '1')
            decimalNum += pow(2, -i);

    printf("The converted decimal number is:\n");
    printf("%f\n", decimalNum);

    return 0;

}
float pow (int m,int n)
{
    float sum=1;

    int i;
    if (n>0)
    {
        for (i=1;i<=n;i++)
            sum=m*sum;
    }
    else
    {
        if (n==0)
            sum=1;
        else
        {
            if (n<0)
            {
                for (i=1;i<=(-n);i++)
                    sum=sum*(1/m);
            }
        }
    }
    return(sum);
}

差点没看晕掉。。。。