c - 如何将字符串作为输入，然后在新行中打印每个单词

Question

i want to to take a string as a input and then print each word in a new line.

Condition is: printed word must be stored in a array and every word will be removed from array after printing it.

#include<stdio.h>
int main() {
  char s[100], tmp[20];
  int i=0,space=0,k;
  scanf("%[^\n]", s);

  while(s[i]!='\0'){
    if(space==0) tmp[i]=s[i]; //copying word only
    else tmp[i-(k+1)]=s[i];   //copying word only

    if((s[i]==' ')||(s[i+1]=='\0')){
      tmp[i+1]='\0';
      space++;
      printf("%s\n", tmp); //printing word from an array

      for(int j=0; tmp[j]!='\0'; j++) tmp[j]='\0'; //erasing this array for reuse
      k=i++; //(i++) for skip space and 'k' for starting index from tmp[0]
      if(s[i]=='\0') i--; //when null don't need to increase i for skip space
    }
  i++;
  }
  return 0;
}

谁能帮我理解这个问题？

Answer 1

这明显违反了您的条件，但该条件不合适，我认为读者值得了解如何在没有它的情况下做到这一点。这种方法的主要好处是您不会对输入长度施加任意限制。 (在原始代码中，输入不得超过 100 个字节。)我假设您的问题陈述只是实现 tr -s '[[:space:]]'\\n，您可以执行哪种情况:

#include <stdio.h>
#include <ctype.h>

/* Simple implementation of tr -s '[[:space:]]' \\n */

int
main(void)
{
        int in_space = 0;
        int c;
        while( (c = getchar()) != EOF  ) {
                if(isspace(c)) {
                        if( !in_space )
                                putchar('\n');
                        in_space = 1;
                } else {
                        in_space = 0;
                        putchar(c);
                }
        }
        if(!in_space)
                putchar('\n');
        return 0;
}

可以稍微简化(IMO，上面的内容过于冗余):

#include <stdio.h>
#include <ctype.h>

/* Simple implementation of tr -s '[[:space:]]' \\n */

int
main(void)
{
        int c;
        int last = '\n';
        while( (c = getchar()) != EOF  ) {
                c = isspace(c) ? '\n' : c;
                if( c != '\n' || last != '\n' )
                        putchar(c);
                last = c;
        }
        if( last != '\n' )
                putchar(c);
        return 0;
}

甚至:

#include <stdio.h>
#include <ctype.h>

/* Simple implementation of tr -s '[[:space:]]' \\n */

void
dedup(int c)
{
        static int last = '\n';
        if( c != '\n' || last != '\n' )
                putchar(c);
        last = c;
}

int
main(void)
{
        int c;
        while( (c = getchar()) != EOF  ) {
                dedup( isspace(c) ? '\n' : c);
        }
        dedup('\n');
        return 0;
}