today 15:42:36
#include <stdio.h>
#define M 20
int f(char a[])//f是用来去掉空格的函数
{
    int  i ;
    i=0;
    while (a[i]='\n')
       i++;
    i--;
    while (i>0&& a[i]==' '||a[i]=='\t')
      i--;
      if(i>0)
      {
        i++;
        a[i]='\n';
        i++;
        a[i]='\0';
      }
      return 1;
}

int getline (char s[],int lim )
{
    int c,i,j;
    j=0;
    for (i=0;(c=getchar())!=EOF&&c!='\n';i++)
    {
       if(lim<i-2)
       {
          s[j]=c;
           ++j;
       }
       if(c=='\n')
       {
           s[j]=c;
           ++j;
           ++i;
       }
       s[j]='\0';
      
    }
    return i;
}
int main ()
{
       char a[M];
       while (getline (a,M)>0)
       if(f(a)>0)
       printf ("%s",a);
       return 0;
}

编译通过，运行错误，怎么改好

#include <stdio.h>
#include <string.h>

int main(void) {
    int i = -1;
    char data[20] = {0}, *p = NULL;
    const char spaces[] = " \t";
    while(++i < 20) {
        if((data[i] = getchar()) == '\n')
            break;
    }

    p = strtok(data, spaces);

    while(p) {
        printf("%s", p);
        p = strtok(NULL, spaces);
    }

    printf("\n");
    return 0;
}