#include <stdio.h>
#include <math.h>
int main()
{
float norms (float);              //声明五个原函数 norms（标准身高），normswei（标准体重），percentwei（体重差额百分比）
float pcdif (float , float);      // pcdif（身高差额的百分比）， showit（显示计算的结果)
void showit(float , float ,float ,float);
float normswei (float);
float percentwei (float, float);


int years, months;                //定义变量years ，months ，height ，normht ，age ，perdif
float height ,normht;
float age , perdif;
float weight;  //定义weight（体重）percentweight(体重差额)
float percentweight, normweight;

     /*这是输入部分*/   
printf("\n How old (in years) is this child? ");
scanf("%d", &years);
printf("How many months since the child's birthday? ");
scanf("%d",&months);

age = years + months/12.0;                      //年龄转换
printf("Enter the child's height (in inches): ");
scanf("%f" ,&height);

printf("Enter the chlid's weight (in kilogram): ");
scanf("%f",&weight);


    /*这是计算部分*/
normht = norms(age);
perdif = pcdif(height, normht);
normweight = normswei(age);
percentweight = percentwei(weight ,normweight);

showit(normht, perdif, normweight, percentweight);

 
    return 0;
}


/*下面是函数的占位函数*/
float norms  (float age)
{
    #define MINAGE 6.0
float agedif, avght;

agedif = age - MINAGE;
avght = -0.25*pow(agedif,2) + 3.5*agedif + 45.0;
return(avght);
}


float pcdif (float actual, float base)
{
return(actual - base)/base * 100.0;
}

float normweight(float age)
{
    float Norm;
    Norm=0.5*(age - 6)+5.0*(age - 6 ) + 48;
    return (Norm);
}


float percentweight(float actualwei, float normweights)
{
    return((actualwei - normweights)/normweights * 100.0);
}


void showit(float normht, float perdif, float normweight, float percentweight)
{
printf("\nThe average height in inches is: %5.2f\n", normht);
printf("The actual height deviates from the norm by: %6.2f%c",perdif,'%');
printf("\nThe average weight in kilogram is: %5.2f\n", normweight);
printf("The actual weight deviates from the norm by: %6.2f%c",percentweight,'%');   
}



35行和36行出问题了，编译提示说“undefined reference to'normswei(float)'”
可是我明明已经定义了

程序全复制上来了吗?看到函数声明,没看到函数本身啊.也许我眼花了,我再仔细找找.

全贴上来了，函数在下面

找了半天都没有找到normswei(float)的定义啊！难到眼花勒！

float norms  (float age)
{
    #define MINAGE 6.0
float agedif, avght;

agedif = age - MINAGE;
avght = -0.25*pow(agedif,2) + 3.5*agedif + 45.0;
return(avght);
}


float pcdif (float actual, float base)
{
return(actual - base)/base * 100.0;
}

float normweight(float age)
{
    float Norm;
    Norm=0.5*(age - 6)+5.0*(age - 6 ) + 48;
    return (Norm);
}


float percentweight(float actualwei, float normweights)
{
    return((actualwei - normweights)/normweights * 100.0);
}


void showit(float normht, float perdif, float normweight, float percentweight)
{
printf("\nThe average height in inches is: %5.2f\n", normht);
printf("The actual height deviates from the norm by: %6.2f%c",perdif,'%');
printf("\nThe average weight in kilogram is: %5.2f\n", normweight);
printf("The actual weight deviates from the norm by: %6.2f%c",percentweight,'%');   
}

[ 本帖最后由 liangjinchao 于 2011-5-22 21:08 编辑 ]

原因找到了，是我大意了，把函数norswei和percentwei写成norweight和percentweight了正确的应该是：

float norsmwei(float age)
{
    float Norm;
    Norm=0.5*(age - 6)+5.0*(age - 6 ) + 48;
    return (Norm);
}


float percentwei(float actualwei, float normweights)
{
    return((actualwei - normweights)/normweights * 100.0);
}


void showit(float normht, float perdif, float normweight, float percentweight)
{
printf("\nThe average height in inches is: %5.2f\n", normht);
printf("The actual height deviates from the norm by: %6.2f%c",perdif,'%');
printf("\nThe average weight in kilogram is: %5.2f\n", normweight);
printf("The actual weight deviates from the norm by: %6.2f%c",percentweight,'%');   
}