C语言 CS50可读性结果问题

Question

我编写了以下代码来解决可读性实验。它编译得很好，没有问题。问题是在结果中，由于未知的原因，它总是计算s_avg为零。s_avg is100个单词的平均句子数。

#include <ctype.h>
#include <cs50.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
//prototypes
int count_letters (string text);
int count_words(string text);
int count_sent(string text);
int main(void)
{
// get the user to prompt part of the story
string story = get_string("Text: n");

//variables
int letters = count_letters(story);
int words = count_words(story);
int sentences = count_sent(story);

//show results
printf("%i letter(s)n",letters);
printf("%i word(s)n",words);
printf("%i sentence(s)n",sentences);

// Calculate average number of letters & sentences per 100 words
int l_avg = (letters/words)*100;
int s_avg = (sentences/words)*100;

// Calculate Coleman-Liau index
int index = round(0.0588 * l_avg - 0.296 * s_avg - 15.8);

// check grade level
if(index<1)
{
printf("Before Grade 1n");
}
else if(index>16)
{
printf("Grade 16+n");
}
else
{
printf("Grade %in",index);
}
}
//count the number of letters
int count_letters (string text)
{
int l = 0;
for(int i=0,n=strlen(text); i<n; i++)
{
if((text[i]>=97 && text[i]<=122)||(text[i]>=65 && text[i]<=90))
{
l++ ;
}
}
return l;
}
//count the number of words
int count_words(string text)
{
int w = 1;
for(int i=0,n=strlen(text); i<n; i++)
{
if (text[i]==32)
{
w++ ;
}
}
return w ;
}
//count the number of sentences
int count_sent(string text)
{
int s=0;
for(int i=0,n=strlen(text); i<n; i++)
{
if ((text[i]==46) || (text[i]==33) || (text[i]==63))
{
s++ ;
}
}
return s;
}

我不知道为什么它一直计算int s_avg = (sentences/words)*100;为零。我意识到使用debug50工具。

Answer 1

用于计算平均字母数&句，使用double类型的变量代替。

double l_avg = ((double)letters / (double)words)*100;
double s_avg = ((double)sentences / (double)words)*100;

Answer 2

C中的整数除法得到的是整数，而不是浮点数。您必须显式地将被除数和除数转换为float:

int i = 5 / 4;
printf("%d", i); // prints 1
float f = (float)5 / (float)4;
printf("%f", f); // prints 1.250000

所以，int s_avg = (sentences/words)*100应该是:

float s_avg = (float)sentences / (float)words * 100;