void deep(int fl, char pathbytes[]) {
char path[N];
char operator[]= {"+-*/"};
int len;
strcpy(path, pathbytes);
len = strlen(pathbytes);
for(int i=0; i<5; i++) {
if (i<4) {
path[len]= operator[i];
path[len+1]=digits[fl+1];
path[len+2]='\0';
} else {
path[len]=digits[fl+1];
path[len+1]='\0';
}
if (fl < 7) {
deep(fl+1, path);
} else {
nTop=-1, oTop=-1;
if (eval(path) == 100) {
kind++;
printf("%4d %s = 100\n",kind, path);
}
}
}
}