mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 11:37:35 +00:00
60 lines
1.8 KiB
C
60 lines
1.8 KiB
C
#ifndef NSYNC_TESTING_HEAP_H_
|
|
#define NSYNC_TESTING_HEAP_H_
|
|
/* clang-format off */
|
|
|
|
/* A heap.
|
|
Optionally, elements may have storage for the index to allow deletions from
|
|
arbitrary elements. A "set" operation sets the field. Use heap_no_set when
|
|
no field is available.
|
|
|
|
Let:
|
|
set (e,i) sets the index field of the element e to i
|
|
lt (e0, e1) returns whether element e0 < e1
|
|
|
|
If
|
|
"a" is an array,
|
|
"n" is is its length,
|
|
then
|
|
To add an element e:
|
|
ensure there are n+1 elements in a[]
|
|
heap_add (a, n, lt, set, e); // modifies n
|
|
To remove element i:
|
|
heap_remove (a, n, lt, set, i); // modifies n
|
|
To replace element i with element e:
|
|
heap_adjust (a, n, lt, set, i, e);
|
|
*/
|
|
|
|
|
|
#define h_up_(i) (((i)-1) >> 1)
|
|
#define h_down_(i) (((i)<<1) + 1)
|
|
|
|
#define h_updownall_(up,a,n,i,lt,set,v,s) \
|
|
do { \
|
|
int i_ = (i); \
|
|
int n_ = (n); \
|
|
int j_; \
|
|
if (up) { \
|
|
for (; i_!=0 && ((j_ = h_up_ (i_)), lt ((v), (a)[j_])); i_ = j_) { \
|
|
(a)[i_] = (a)[j_]; \
|
|
set ((a)[i_], i_); \
|
|
} \
|
|
} else { \
|
|
for (; (j_ = h_down_ (i_)) < n_ && ((j_ += (j_+1 < n_ && \
|
|
lt ((a)[j_+1], (a)[j_]))), lt ((a)[j_], (v))); i_ = j_) { \
|
|
(a)[i_] = (a)[j_]; \
|
|
set ((a)[i_], i_); \
|
|
} \
|
|
} \
|
|
s; \
|
|
} while (0)
|
|
|
|
#define heap_no_set(a,b) ((void)0)
|
|
|
|
#define heap_add(a,n,lt,set,v) h_updownall_ (1, (a), 0, \
|
|
(n), lt, set, (v), ((a)[i_]=(v), set ((a)[i_], i_), (n)++))
|
|
#define heap_remove(a,n,lt,set,i) h_updownall_ (lt ((a)[n_], (a)[i_]), (a), --(n), \
|
|
(i), lt, set, (a)[n_], ((a)[i_]=(a)[n_], set ((a)[i_], i_)))
|
|
#define heap_adjust(a,n,lt,set,i,v) h_updownall_ (lt ((v), (a)[i_]), (a), (n), \
|
|
(i), lt, set, (v), ((a)[i_]=(v), set ((a)[i_], i_)))
|
|
|
|
#endif /*NSYNC_TESTING_HEAP_H_*/
|