a simple bit vector

#include <stdio.h>

#define BYTE_LEN 8

unsigned int direct_address_search(int T[], int k) {
  int byte_offset = k / BYTE_LEN;
  int bit_offset = k % BYTE_LEN;
  return (T[byte_offset] >> bit_offset) & 1u;
}


void direct_address_insert(int T[], int k) {
  int byte_offset = k / BYTE_LEN;
  int bit_offset = k % BYTE_LEN;
  T[byte_offset] |= (1u << bit_offset);
}

void direct_address_delete(int T[], int x) {
  int byte_offset = x / BYTE_LEN;
  int bit_offset = x % BYTE_LEN;
  T[byte_offset] &= (0u << bit_offset);
}

void info(unsigned int T[], int size) {
  int i;
  for (i = 0; i < size; i++) {
    printf("%d: %#X\n", i, T[i]); 
  }
}


int main(int argc, const char *argv[]) {
  /* A 16 bit bit-vector */
  unsigned int T[2] = {0};
  direct_address_insert(T, 0);
  direct_address_insert(T, 2);
  printf("bit 1 is %d\n", direct_address_search(T, 1));
  printf("bit 2 is %d\n", direct_address_search(T, 2));
  info(T, 2);
  direct_address_delete(T, 0);
  direct_address_delete(T, 2);
  return 0;
}