Question

我是编程的新手。

我在C编程语言（K＆amp; R）练习1-13的解决方案代码中有6个问题。任务是编写一个打印单词长度直方图的程序。如图所示。

我已粘贴下面的代码以及我为帮助我理解所做的笔记。

我的问题紧挨着我有疑问的代码的各个部分。提前谢谢！

int main ()
{

int c, i, nc, state;
int len;                      /* length of each bar           */
int maxvalue;                 /* maximum value for wl[]       */
int ovflow;                   /* number of overflow words     */
int wl[MAXWORD];              /* word length counters. Defining an int array with 11 character variables. This is the same as saying int wl[11]           */


state = OUT;
nc = 0;                       /* number of chars in a word    */
ovflow = 0;                   /* number of words              */

下面这个for循环的目的是什么？它是否初始化数组？

    for (i = 0; i < MAXWORD; ++i)
      wl[i] = 0;


while ((c = getchar()) != EOF) //get a character
{
  if (c == ' ' || c == '\n' || c == '\t') // if c is a blank, new line or tab
  {
      state = OUT;  // we are outside a word.

下面我们有(nc > 0)虽然上面声明了nc，nc如何更改？就像用户如何改变它一样？ nc的输入在哪里？

      if (nc > 0) 

          if (nc < MAXWORD) //if the number of characters is less than the maxword length counter.
          {
              ++wl[nc]; // increase the number of elements/number of characters in the array by 1.  
          }

++wl[nc]中的增量运算符增加1？它会增加数组wl吗？ nc中++wl[nc]的重要性是什么？

          else
          {
              ++ovflow; // if nc is greater than the maxword however, increase the overflow by 1
          } 

      nc = 0;
  }

上面，nc = 0是否会重置字符数？

  // The beginning of a new word

  else if (state == OUT) {  //if state is out or better put, if we are not in a word
      state = IN;             // In that case, upon accepting a new character, we are at the start of a new word hence state is in.
      nc = 1;                 // and upon accepting a character, the number of characters is 1.
  }

  // inside a word
  else 
  {
      ++nc;                   // if not outside a word or in a word, increase the number of characters by 1

  }

}

我们在下面的行中初始化maxvalue？

maxvalue = 0 ;
for (i = 1; i < MAXWORD; ++i) //Run a for loop until i is 10. Since MAXWORD length counter is 11.
  {
      if (wl[i] > maxvalue) //if the elements in the array is greater than the max number of elements allowed in the array
              maxvalue = wl[i]; //the max amount of elements allowed in the array is the same as the number of elements in the array. 
      }

我没有得到这部分代码。有人可以向我解释一下吗？

for (i = 1; i < MAXWORD; ++i)
{
  printf("%5d - %5d : ", i, wl[i]); //i refers to the word length while wl[i] is the frequency of its occurence.
  if (wl[i] > 0) {
      if ((len = wl[i] * MAXHIST / maxvalue) <= 0)
          len = 1;

  }

  else
      len = 0;
  while (len > 0) 
  {
      putchar ('*');
      --len;

  }
  putchar('\n');

}
if (ovflow > 0)
  printf("There are %d words >= %d\n", ovflow, MAXWORD);

Answer 1

是
已在else if (state == OUT)
nc'th数组中的wl元素递增（array [1]是数组中的第二个元素，因此第n个元素实际上是nc + 1。 ..）
是
是
for循环打印字计数器（哪个字是它）及其长度。

如果特定单词的长度大于0 len则获取值wl[i] * MAXHIST / maxvalue然后检查为0.如果它等于0则len变为1。

否则：len变为1

毕竟这个程序打印len次＆＃39; *＆＃39;然后是换行符

关于C编程语言（K＆amp; R）的问题 - 练习1-13

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