/**
* Find in/out
*/
void find_inout()
{
struct block *b = first_block;
struct block *tmpb = (struct block *) malloc(sizeof(struct block));
int i;
int change = 1;
int oldlen;
calc_pred();
DEBUG(print_pred());
while(b) {
b->defin.ini = 0;
copy_set(b, OUT_SET, b, GEN_SET);
b = b->next;
}
while(change) {
change = 0;
b = first_block;
while(b) {
for(i = 0; i < b->predi; i++)
union_set(b, IN_SET, b->pred[i], OUT_SET);
copy_set(tmpb, IN_SET, b, IN_SET);
sub_set(tmpb, IN_SET, b, KILL_SET);
union_set(tmpb, IN_SET, b, GEN_SET);
oldlen = b->defin.outi;
// According to algorithm I should do what is commented belove
/*
copy_set(oldb, OUT_SET, b, OUT_SET);
copy_set(b, OUT_SET, tmpb, IN_SET);
if(!equal_set(oldb, OUT_SET, b, OUT_SET))
change = 1;
*/
// but since out[b] = gen[b] we can do
// 1. union agains copy
// 2. compare set's length to see if it's changed
union_set(b, OUT_SET, tmpb, IN_SET);
if(oldlen != b->defin.outi)
change = 1;
b = b -> next;
}
}
}
void sub_set(char* charset, int position_count, int sequence[], int length)
{
int lcv;//loop control variable to check every elements in the array
if(position_count == length)//Base case: if the sequence array has been fully updated then print the array
{
for(lcv = 0; lcv < length; lcv++)//print out the elements in the character array which have been selected by the sequence integer array
{
if(sequence[lcv])//if the value at the same position in the integer array is one, then we can print this character
{
printf("%c ", charset[lcv]);
}
}
printf("\n");
}
else//Inductive case: if not,we need to keep updating the sequency array to select which characters in the charset array to print out
{
sequence[position_count] = 0;//first case:set the value to zero, so that we don't print the character
sub_set(charset, position_count + 1, sequence, length);//recursive call to deal with the rest characters in the charset array
sequence[position_count] = 1;//second case:set the value to one, so that we can print the character
sub_set(charset, position_count + 1, sequence, length);//recursively call to deal with the rest characters in the charset array
}
}
void subset(char * charset, int length)
{
int sequence[length];//the integer array keep tracking which element in the charset should be print out
int lcv;//loop control variable to check all the elements in the integer array and character array
int position_count = 0;//the position count variable to represent which position in the character array needed to be printed out
for(lcv = 0;lcv < length;lcv++)//initialize the integer array
{
sequence[lcv] = 0;
}
printf("subset of ");
for(lcv = 0;lcv < length;lcv++)//first print out all the characters in the charset array
{
printf("%c ", charset[lcv]);
}
sub_set(charset, position_count, sequence, length);//call the recursive function
}