K&R练习1-8改进

#include <stdio.h>

int main() {
    int c, last_char_was_space = 0;
    while ((c = getchar()) != EOF) {
        if (c == ' ' || c == '\t') {
            if (!last_char_was_space) {
                putchar(' ');
                last_char_was_space = 1;
            }
        } else {
            putchar(c);
            last_char_was_space = 0;
        }
    }
    return 0;
}

#include <stdio.h>

int main() {
    int c, last_char_was_space = 0, at_end_of_line = 0;
    while ((c = getchar()) != EOF) {
        if (c == '\n') {
            at_end_of_line = 0;
        }
        if (c == ' ' || c == '\t') {
            if (!last_char_was_space && !at_end_of_line) {
                putchar(' ');
                last_char_was_space = 1;
            }
        } else {
            putchar(c);
            last_char_was_space = 0;
            at_end_of_line = (c == '\n');
        }
    }
    return 0;
}