Hi am trying to read out the contents of my bit array but for some reason it only works for the first byte index.Code:int letterToIndex(char c){ int index=(int)c - (int)'a'; return index; } // a method that converts an integer representation to an alphabet char indexToAlpha(int index){ char c= (char)( (int)('a')+ index); return c; } // a bit vector struct struct bitset{ int size; unsigned char *bitcontents; }; /*initialisng a bitset struct to the size of the elements */ struct bitset * bitset_new(int size){ struct bitset * p= ( struct bitset *) malloc(sizeof(*p)); p->size= size/(sizeof(unsigned char) * 8); if(size % (sizeof(unsigned char) *8) !=0) p->size = p->size+1; p->bitcontents= (unsigned char*) malloc( sizeof(unsigned char) * p->size); return p; } /*checks to see if an integer item is in the set *returns 1 if in the set, 0 if not, and -1 if 'item' is out of bounds */ int bitset_lookup(struct bitset * p, int item) { int block=item/(sizeof(unsigned char) * 8); int bitindex= item % (sizeof(unsigned char) * 8); if(block >= p->size){ return -1; } if((p->bitcontents[block] & (1<< bitindex) )) return 1; else return 0; } // add an item, with number 'item' to the set // (returns 0 if item is out of bounds, 1 otherwise) // has no effect if the item is already in the set int bitset_add(struct bitset * p, int item){ int block= item / (sizeof(unsigned char) * 8); // determines what index of my bitcontents to put the bit in int bitindex= item% (sizeof(unsigned char) * 8); if(block< p->size){ p->bitcontents[block]=p->bitcontents[block] ^ 1<<bitindex; // printf("xxxx%d/n",p->bitcontents[0]); return 1; } return 0; void bitset_union(struct bitset * destination ,struct bitset * src1,struct bitset *src2){ int i=0; while(i< destination->size){ destination->bitcontents[i]= src1->bitcontents[i] | src2->bitcontents[i]; i++; } } } void toString(struct bitset *p,char buffer[]){ int t=0; int i=0;int j=0; int z=8; for(;i< p->size;i++){ for(;j<8;j++){ if(p->bitcontents[i] & 1<<j) putchar(indexToAlpha(j)); } } } int main(int argc, char** argv) { struct bitset *a; struct bitset *b; struct bitset *destination; char buffer[27]; char bufferoutput[255]; char buuu[27]; int index=0; int lookup=0; // index =letterToIndex(letter); a=bitset_new(26); b=bitset_new(26); destination=bitset_new(26); // lookup = bitset_lookup(a, index); printf("please enter a string for set a"); fgets(buffer,26,stdin); int i=strlen(buffer)-1; if(buffer[i]=='\n') buffer[i]='\0'; // printf("the set of characters apperaing in set a"); // printf("%s\n",buffer); i=0; // setting my bits in my bit set vectors while(buffer[i]!='\0') { bitset_add(a, letterToIndex(buffer[i++])); } printf("please enter a string for set b"); fgets(buffer,26,stdin); i=strlen(buffer)-1; if(buffer[i]=='\n') buffer[i]='\0'; // printf("the set of characters apperaing in set b"); // printf("%s\n",buffer); i=0; while(buffer[i]!='\0'){ bitset_add(b, letterToIndex(buffer[i++])); } bitset_union(destination,a,b); lookup = bitset_lookup(destination, 11); printf("%d\n",lookup); toString(destination, bufferoutput);
Originally Posted by CommonTater
