使用 getchar() 计算 C 中的新行、新制表符和空格

Question

我创建了一个计算新行、新单词、sapces 和标签的表格。 我成功计算了所有这些，但问题出在 output 上：

我试图只用我正在计算的结果打印一行，但 output 是整个计数（增量）。

#include <stdio.h>
#define IN 1
#define OUT 0

int main()
{
    int c,nl,nw,nc,state;
    int newspace, tabchar;
    state = OUT;
    int id;

    nl = nw = nc = id = 0;
    newspace = tabchar = 0;
    printf("+===============================================================+\n");
    printf("|                       WORDS, NEW LINE COUNTER                 |\n");
    printf("+======+==========+==========+============+===========+=========+\n");
    printf("|  ID  | NEW LINE | NEW WORD | CHAR COUNT | NEW SPACE | NEW TAB |\n");
    printf("+===============================================================+\n");

    while ((c = getchar()) != EOF)
    {
        ++nc;
        if(c == '\n')
            ++nl;
        if(c == ' ' || c == '\n' || c == '\t')
            state = OUT;
        if(c == ' ')
            newspace++;
        if(c == '\t')
            tabchar++;
        else if(state == OUT)
        {
            state = IN;
            ++nw;
        }
        id = nl + 1; 
        printf("|  %d  |     %d    |       %d   |       %d      |      %d     |     %d   |\n", id, nl, nw, nc, newspace, tabchar);
    }
}

错误 OUTPUT：

+===============================================================+
|                       WORDS, NEW LINE COUNTER                 |
+======+==========+==========+============+===========+=========+
|  ID  | NEW LINE | NEW WORD | CHAR COUNT | NEW SPACE | NEW TAB |
+===============================================================+
I am counting spaces and tab here
|  1  |   0    |      1   |      1   |     0   |     0   |
|  1  |   0    |      2   |      2   |     1   |     0   |
|  1  |   0    |      2   |      3   |     1   |     0   |
|  1  |   0    |      2   |      4   |     1   |     0   |
|  1  |   0    |      3   |      5   |     2   |     0   |
|  1  |   0    |      3   |      6   |     2   |     0   |
|  1  |   0    |      3   |      7   |     2   |     0   |
|  1  |   0    |      3   |      8   |     2   |     0   |
|  1  |   0    |      3   |      9   |     2   |     0   |
|  1  |   0    |      3   |      10   |     2   |     0   |
|  1  |   0    |      3   |      11   |     2   |     0   |
|  1  |   0    |      3   |      12   |     2   |     0   |
|  1  |   0    |      3   |      13   |     2   |     0   |
|  1  |   0    |      4   |      14   |     3   |     0   |
|  1  |   0    |      4   |      15   |     3   |     0   |
|  1  |   0    |      4   |      16   |     3   |     0   |
|  1  |   0    |      4   |      17   |     3   |     0   |
|  1  |   0    |      4   |      18   |     3   |     0   |
|  1  |   0    |      4   |      19   |     3   |     0   |
|  1  |   0    |      4   |      20   |     3   |     0   |
|  1  |   0    |      5   |      21   |     4   |     0   |
|  1  |   0    |      5   |      22   |     4   |     0   |
|  1  |   0    |      5   |      23   |     4   |     0   |
|  1  |   0    |      5   |      24   |     4   |     0   |
|  1  |   0    |      6   |      25   |     5   |     0   |
|  1  |   0    |      6   |      26   |     5   |     0   |
|  1  |   0    |      6   |      27   |     5   |     0   |
|  1  |   0    |      6   |      28   |     5   |     0   |
|  1  |   0    |      7   |      29   |     6   |     0   |
|  1  |   0    |      7   |      30   |     6   |     0   |
|  1  |   0    |      7   |      31   |     6   |     0   |
|  1  |   0    |      7   |      32   |     6   |     0   |
|  1  |   0    |      7   |      33   |     6   |     0   |
|  2  |   1    |      8   |      34   |     6   |     0   |

所需 OUTPUT：

+===============================================================+
|                       WORDS, NEW LINE COUNTER                 |
+======+==========+==========+============+===========+=========+
|  ID  | NEW LINE | NEW WORD | CHAR COUNT | NEW SPACE | NEW TAB |
+===============================================================+
I am counting spaces and tab here
|  2  |   1    |      8   |      34   |     6   |     0   |

我究竟做错了什么？ output 似乎几乎是正确的。 在我看来，潜在的问题可能是程序无法正确理解EOF ，特别是以下语句while ((c = getchar()) != EOF)但我不知道为什么。

感谢您指出解决方案的正确路线。

Answer 1

它实际上运行良好，但您在每次迭代时都在打印。 对于您想要的 output，您应该将printf语句放在 while 块结束之后。

while ((c = getchar()) != EOF)
{
    ++nc;
    if(c == '\n')
        ++nl;
    if(c == ' ' || c == '\n' || c == '\t')
        state = OUT;
    if(c == ' ')
        newspace++;
    if(c == '\t')
        tabchar++;
    else if(state == OUT)
    {
        state = IN;
        ++nw;
    }
    id = nl + 1; 
    printf("|  %d  |     %d    |       %d   |       %d      |      %d     |     %d   |\n", id, nl, nw, nc, newspace, tabchar);
}

应该：

while ((c = getchar()) != EOF)
{
    ++nc;
    if(c == '\n')
        ++nl;
    if(c == ' ' || c == '\n' || c == '\t')
        state = OUT;
    if(c == ' ')
        newspace++;
    if(c == '\t')
        tabchar++;
    else if(state == OUT)
    {
        state = IN;
        ++nw;
    }
    id = nl + 1; 
    
}

printf("|  %d  |     %d    |       %d   |       %d      |      %d     |     %d   |\n", id, nl, nw, nc, newspace, tabchar);