adam/cobm
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Fix and (other) improvement.

Browse Source 
git-svn-id: svn://svn.code.sf.net/p/sc2/code/trunk@2452 8092fc87-c524-0410-9efc-e669fe64eaf9
This commit is contained in:
meep-eep
2006-10-22 23:50:47 +00:00
parent 099c4a0910
commit fb54ca7b54
1 changed files with 36 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files
sc2/src/sc2code/libs/heap/heap.c
+40 -35
View File
@@ -21,6 +21,7 @@
#include <assert.h>
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include "port.h"
static inline size_t nextPower2(size_t x);
@@ -32,6 +33,7 @@ Heap_resize(Heap *heap, size_t size) {
heap->size = size;
}
// Heap inv: comparator(parent, child) <= 0 for every child of every parent.
Heap *
Heap_new(HeapValue_Comparator comparator, size_t initialSize, size_t minSize,
double minFillQuotient) {
@@ -74,7 +76,7 @@ Heap_add(Heap *heap, HeapValue *value) {
while (i > 0) {
size_t parentI = (i - 1) / 2;
if (heap->comparator(heap->entries[i], heap->entries[parentI]) <= 0)
if (heap->comparator(heap->entries[parentI], value) <= 0)
break;
heap->entries[i] = heap->entries[parentI];
@@ -83,6 +85,7 @@ Heap_add(Heap *heap, HeapValue *value) {
}
heap->entries[i] = value;
heap->entries[i]->index = i;
fprintf(stderr, "%d heap entries.\n", heap->numEntries);
}
HeapValue *
@@ -92,15 +95,6 @@ Heap_first(const Heap *heap) {
return heap->entries[0];
}
static inline void
swapEntries(Heap *heap, size_t i0, size_t i1) {
HeapValue *temp = heap->entries[i0];
heap->entries[i0] = heap->entries[i1];
heap->entries[i0]->index = i0;
heap->entries[i1] = temp;
heap->entries[i1]->index = i1;
}
static void
Heap_removeByIndex(Heap *heap, size_t i) {
assert(heap->numEntries > i);
@@ -108,35 +102,46 @@ Heap_removeByIndex(Heap *heap, size_t i) {
heap->numEntries--;
if (heap->numEntries != 0) {
heap->entries[i] = heap->entries[heap->numEntries];
// Restore the heap invariant. We're shifting entries into the
// gap that was created until we find the place where we can
// insert the last entry.
for (;;) {
size_t childI = i * 2 + 1;
// The two children are childI and 'childI + 1'.
if (childI + 1 >= heap->numEntries) {
// There is no right child.
if (childI >= heap->numEntries) {
// There is no left child either.
break;
}
if (heap->comparator(heap->entries[childI + 1],
heap->entries[childI]) < 0) {
// The right child is the child with the lowest value.
childI++;
}
}
// childI is now the child with the lowest value.
if (heap->comparator(heap->entries[heap->numEntries],
heap->entries[childI]) <= 0) {
// The last entry goes here.
break;
}
// Move the child into the gap.
heap->entries[i] = heap->entries[childI];
heap->entries[i]->index = i;
// Restore the heap invariant:
for (;;) {
size_t leftI = i * 2 + 1;
size_t rightI = leftI + 1;
size_t newI;
if (rightI < heap->numEntries) {
// rightI is unused.
if (leftI < heap->numEntries)
break;
// leftI is used, rightI is unused.
if (heap->comparator(heap->entries[i],
heap->entries[leftI]) < 0)
swapEntries(heap, i, leftI);
break;
// and repeat for the child.
i = childI;
}
newI = (heap->comparator(heap->entries[leftI],
heap->entries[rightI]) >= 0) ? leftI : rightI;
if (heap->comparator(heap->entries[i], heap->entries[newI]) >= 0)
break;
swapEntries(heap, i, newI);
i = newI;
}
// Fill the gap with the last entry.
heap->entries[i] = heap->entries[heap->numEntries];
heap->entries[i]->index = i;
}
// Resize if necessary: