练习1-10

int main(int argc, char** argv) {
    int nspace = 0;
    int c;
    while((c=getchar())!=EOF){
        if(c=='\t')
            printf("\\t");
        if(c=='\\')
            printf("\\");
        if(c!='\b')
            if(c!='\t')
                if(c!='\\')
                    putchar(c);
    }
    return 0;
}