The C Programming Language Exercise

1-9 :

Write a program to copy its input to its output, replacing each string of one or more blanks by a single blank. 

point : change the entry of space putchar when there has met a space already.

#include <stdio.h>
main(){
    ;
    ;
    while((c = getchar()) != EOF){
        if(c == ' '){
            ){
                putchar(c);
                inspace = ;
            }
        }
        else{
            inspace = ;
            putchar(c);
        }
    }
}

count the numbers of word:

 #include <stdio.h>
 #define IN 1  //no ";"
 #define OUT 0

 main(){
     int c ;
     int state = OUT;
     int nc, nw, nl;
     nc = nw = nl = ;  //注意初始化 

     while((c = getchar()) != EOF){
         nc ++;
         if(c == '\t')
             nl++;
         if(c == ' ' || c == '\t' || c == '\n') {
             state = OUT;
         }
         else if(state == OUT){  //if state is OUT here, means in the word, chage state and ++nw
             state = IN;
             nw++;
         }
     }
     printf("%d %d %d",nc, nw, nl);
 }

design a program output the result that every line contains only a word

 #include <stdio.h>
 #define IN 1  //no ";"
 #define OUT 0

 main(){
     int c ;
     ;
     while((c = getchar()) != EOF){
         if(c == ' ' || c == '\t' || c == '\t'){
             ){
                 inspace = ;
                 putchar('\n');
             }
         }
         else{
             inspace = ;
             putchar(c);
         }
     }
     ;
 }