forked from cornerwings/kd-trees
/
build_tree.cpp
174 lines (158 loc) · 3.65 KB
/
build_tree.cpp
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#include <cstdlib>
#include <limits>
#include <float.h>
#include <omp.h>
#include <stdio.h>
#include "rerank.h"
#include "parSort.h"
#include "build_tree.h"
//#define TASKQ_DEPTH 3
int lol = 0;
double** Pv;
int** Iall;
int* flag;
int* aux_global;
int* rerankspace;
int num_leaf_node = 0;
int S;
int D;
int select_dim( int* aux_global, int size, int D) {
int d;
double diff = -DBL_MAX;
int i;
for(i = 0; i < D; i++) {
double* P = Pv[i];
double max = - DBL_MAX;
double min = DBL_MAX;
for(int j = 0; j < size; j++) {
if(P[aux_global[j]] < min) min = P[aux_global[j]];
if(P[aux_global[j]] > max) max = P[aux_global[j]];
if((max - min) > diff){
diff = max - min;
d = i;
}
}
}
return d;
}
void split(tree_node* parent, int* aux_global, int* flag_space, int* rerankspace, int size) {
//printf("Size = %d\n", size);
if(size > S) {
int pivot = (size + 1) / 2;
//int dim = select_dim(aux_global, size, D) ;
int dim = (lol++) % D;
int* Id = Iall[dim];
int i;
for(i = 0; i < size; i++) {
rerankspace[i] = Id[aux_global[i]];
}
rerank(rerankspace, size);
int j = 0;
int k =0;
for( i = 0; i < size; i++) {
if(rerankspace[i] < pivot) {
{
flag_space[k] = aux_global[i];
k++;
}
} else {
{
flag_space[size - size/2 + j] = aux_global[i];
j++;
}
}
}
for(int i = 0; i < size; i++) {
aux_global[i] = flag_space[i];
}
parent->points = NULL;
parent->dimension = dim;
tree_node* left = (tree_node*) malloc(sizeof(tree_node));
tree_node* right = (tree_node*) malloc(sizeof(tree_node));
if(!left) {
printf("Memory could not be allocated for children \n");
exit(-1);
}
if(!right) {
printf("Memory could not be allocated for children \n");
exit(-1);
}
parent->left_child = left;
parent->right_child = right;
left->parent = parent;
right->parent = parent;
#pragma intel omp taskq
{
//building let child
#pragma intel omp task
{
split( left, aux_global, flag_space, rerankspace, size - (size / 2));
}
//building right child
#pragma intel omp task
{
split( right, aux_global + size - (size / 2), flag_space + size - (size / 2), rerankspace + size - (size / 2), size / 2);
}
}
} else {
pts* leaf_points = (pts*) malloc(sizeof(pts));
if(!leaf_points) {
printf("memory couldnot be allocated for leafnode \n");
exit(-1);
}
leaf_points->point_ids = aux_global;
leaf_points->size = size;
parent->points = leaf_points;
parent->left_child = NULL;
parent->right_child = NULL;
}
}
void print_tree (tree_node* parent) {
if((parent-> left_child)) {
print_tree(parent-> left_child);
}
if((parent-> right_child)) {
print_tree(parent-> right_child);
}
if(parent->points) {
int size = parent->points->size;
int* points = parent->points->point_ids;
for(int i =0; i < size; i++) {
printf("%d \n", *(points + i));
}
}
}
tree_node* build_tree(int size) {
flag = new int[size];
aux_global = new int[size];
rerankspace = new int[size];
tree_node* head = (tree_node*) malloc(sizeof(tree_node));
if(!head) {
printf("Memory could not be allocated for tree head\n");
exit(-1);
}
head->parent = NULL;
int i;
#pragma omp parallel for private(i)
for(i = 0 ; i < size; i++) {
aux_global[i] = i;
}
int j = 0;
int k = 0;
#pragma intel omp parallel taskq
{
#pragma intel omp task
split(head, aux_global, flag, rerankspace, size);
}
//print_tree(head);
return head;
}
void delete_tree(tree_node* parent) {
if(parent->right_child)
delete_tree(parent->right_child);
if(parent->left_child)
delete_tree(parent->left_child);
if(parent->points)
free(parent->points);
free(parent);
}