K&R 演習1-12 - うらでぃみーる通信 @Wiki

#include <stdio.h>
 
#define IN  1
#define OUT 0
 
int main(){
    int c, nl, nw, nc, state;
 
    state = OUT;
    nl = nw = nc = 0;
    while(( c = getchar()) != EOF){
        ++nc;
        if( c == '\n')
            ++nl;
        if(c == ' ' || c == '\n' || c == '\t'){
            if(state == IN){
                putchar('\n');
            }
            state = OUT;
        }else if(state == OUT){
            state = IN;
            ++nw;
        }
        if(state == IN){
            putchar(c);
        }
    }
}