add set and clear functions

.gitignore

@@ -1 +1,2 @@
 test
+*swp

bfilter.c

@@ -40,6 +40,7 @@ printbits(int n) {
 int*
 new_bitarray(int size) {
   int *barray = malloc((sizeof (int)) * size);
+
   int i;
   for(i = 0; i < size; i++) {
     barray[i] = 0;
@@ -65,12 +66,30 @@ setbit(int* arr, int k) {
   return 0;
 }
 
+int
+unsetbit(int* arr, int k) {
+  int i = k/32;
+
+  int pos = k % 32;
+
+  unsigned int flag = 1;
+
+  flag = ~(flag << pos);
+
+  arr[i] = arr[i] & flag;
+
+  return 0;
+}
+
 int
 main (void) {
   int *test = new_bitarray(5);
   setbit(test, 6);
   setbit(test, 4);
   setbit(test, 2);
+  unsetbit(test, 6);
+  unsetbit(test, 4);
+  unsetbit(test, 2);
   printbits(test[0]);
   return EXIT_SUCCESS;
 }

bfilter.h

@@ -12,3 +12,4 @@ int printbits(int);
 int *new_bitarray(int);
 
 int setbit(int*, int);
+int unsetbit(int*, int);