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3 changed files with 40 additions and 84 deletions

View file

@ -22,10 +22,10 @@ int main() {
srand(987192345); srand(987192345);
add_rect(0,0,5,4); add_rect(0,0,5,4);
// check_area(20); check_area(20);
add_rect(3,2,6,6); add_rect(3,2,6,6);
// check_area(28); check_area(28);
add_rect(1,-2,8,4); add_rect(1,-2,8,4);
check_area(52); check_area(52);

View file

@ -3,7 +3,6 @@
// //
#include <cassert> #include <cassert>
#include <bit> #include <bit>
#include <stack>
#include "segment_tree.h" #include "segment_tree.h"
SegmentTree::SegmentTree(const std::vector<RectCoord> &coords): SegmentTree::SegmentTree(const std::vector<RectCoord> &coords):
@ -34,75 +33,30 @@ SegmentTree::SegmentTree(const std::vector<RectCoord> &coords):
assert(_nodes.front().segment_length() == coords.back().coord - coords.front().coord); assert(_nodes.front().segment_length() == coords.back().coord - coords.front().coord);
} }
void SegmentTree::add_interval(Interval interval) { void SegmentTree::add_interval(Interval interval, Index node_idx) {
check_integrity();
std::stack<Index> visit_to;
std::stack<Index> update_to;
visit_to.push(0);
while(!visit_to.empty()) {
Index node_idx = visit_to.top();
visit_to.pop();
if (interval.left <= _nodes[node_idx].left_coord && _nodes[node_idx].right_coord <= interval.right) { if (interval.left <= _nodes[node_idx].left_coord && _nodes[node_idx].right_coord <= interval.right) {
add_coverage(node_idx); add_coverage(node_idx);
} else { } else {
if(interval.left < left_child(node_idx).right_coord) { if(interval.left < left_child(node_idx).right_coord) {
visit_to.push(left_child_idx(node_idx)); add_interval(interval, left_child_idx(node_idx));
} }
if(right_child(node_idx).left_coord < interval.right) { if(right_child(node_idx).left_coord < interval.right) {
visit_to.push(right_child_idx(node_idx)); add_interval(interval, right_child_idx(node_idx));
} }
if(!_nodes[node_idx].covered()) { update_covered_length(node_idx);
update_to.push(node_idx);
} }
} }
}
while(!update_to.empty()) {
update_covered_length(update_to.top());
update_to.pop();
}
check_integrity();
}
void SegmentTree::remove_interval(Interval interval) { void SegmentTree::remove_interval(Interval interval, Index node_idx) {
check_integrity();
std::stack<Index> visit_to;
std::stack<Index> update_to;
visit_to.push(0);
while(!visit_to.empty()) {
Index node_idx = visit_to.top();
visit_to.pop();
if (interval.left <= _nodes[node_idx].left_coord && _nodes[node_idx].right_coord <= interval.right) { if (interval.left <= _nodes[node_idx].left_coord && _nodes[node_idx].right_coord <= interval.right) {
remove_coverage(node_idx); remove_coverage(node_idx);
} else { } else {
if(interval.left < left_child(node_idx).right_coord) { if(interval.left < left_child(node_idx).right_coord) {
visit_to.push(left_child_idx(node_idx)); remove_interval(interval, left_child_idx(node_idx));
} }
if(right_child(node_idx).left_coord < interval.right) { if(right_child(node_idx).left_coord < interval.right) {
visit_to.push(right_child_idx(node_idx)); remove_interval(interval, right_child_idx(node_idx));
}
if(!_nodes[node_idx].covered()) {
update_to.push(node_idx);
}
}
}
while(!update_to.empty()) {
update_covered_length(update_to.top());
update_to.pop();
}
check_integrity();
}
void SegmentTree::check_integrity() {
for(Index node_idx = 0 ; node_idx < _nodes.size(); ++node_idx) {
if(_nodes[node_idx].covered()) {
assert(_nodes[node_idx].covered_length == _nodes[node_idx].segment_length());
} else {
if(is_leaf(node_idx)) {
assert(_nodes[node_idx].covered_length == 0);
} else {
assert(_nodes[node_idx].covered_length == \
left_child(node_idx).covered_length + right_child(node_idx).covered_length);
}
} }
update_covered_length(node_idx);
} }
} }

View file

@ -15,7 +15,6 @@ struct TreeNode {
Coordinate right_coord; Coordinate right_coord;
Unit covered_length; Unit covered_length;
inline Unit segment_length(); inline Unit segment_length();
inline bool covered();
}; };
@ -31,9 +30,8 @@ public:
SegmentTree(const std::vector<RectCoord>& coords); SegmentTree(const std::vector<RectCoord>& coords);
inline Unit length_covered_intervals(); inline Unit length_covered_intervals();
void add_interval(Interval interval); inline void add_interval(Interval interval);
void remove_interval(Interval interval); inline void remove_interval(Interval interval);
void check_integrity();
private: private:
inline static Index left_child_idx(Index node_idx); inline static Index left_child_idx(Index node_idx);
@ -43,6 +41,8 @@ private:
inline void add_coverage(Index node_idx); inline void add_coverage(Index node_idx);
inline void remove_coverage(Index node_idx); inline void remove_coverage(Index node_idx);
inline void update_covered_length(Index node_idx); inline void update_covered_length(Index node_idx);
void add_interval(Interval interval, Index node_idx);
void remove_interval(Interval interval, Index node_idx);
inline bool is_leaf(Index node_idx); inline bool is_leaf(Index node_idx);
}; };
@ -65,17 +65,23 @@ Unit SegmentTree::length_covered_intervals() {
return _nodes.front().covered_length; return _nodes.front().covered_length;
} }
void SegmentTree::add_interval(Interval interval) {
add_interval(interval, 0);
}
void SegmentTree::remove_interval(Interval interval) {
remove_interval(interval, 0);
}
void SegmentTree::add_coverage(Index node_idx) { void SegmentTree::add_coverage(Index node_idx) {
++(_nodes[node_idx].coverage); ++(_nodes[node_idx].coverage);
_nodes[node_idx].covered_length = _nodes[node_idx].segment_length(); update_covered_length(node_idx);
} }
void SegmentTree::remove_coverage(Index node_idx) { void SegmentTree::remove_coverage(Index node_idx) {
--(_nodes[node_idx].coverage); --(_nodes[node_idx].coverage);
if(!_nodes[node_idx].covered()) {
update_covered_length(node_idx); update_covered_length(node_idx);
} }
}
Index SegmentTree::left_child_idx(Index node_idx) { Index SegmentTree::left_child_idx(Index node_idx) {
return 2*node_idx + 1; return 2*node_idx + 1;
@ -86,8 +92,9 @@ Index SegmentTree::right_child_idx(Index node_idx) {
} }
void SegmentTree::update_covered_length(Index node_idx) { void SegmentTree::update_covered_length(Index node_idx) {
assert(!_nodes[node_idx].covered()); if (_nodes[node_idx].coverage > 0) {
if (is_leaf(node_idx)) { _nodes[node_idx].covered_length = _nodes[node_idx].segment_length();
} else if (is_leaf(node_idx)) {
_nodes[node_idx].covered_length = 0; _nodes[node_idx].covered_length = 0;
} else { } else {
_nodes[node_idx].covered_length = \ _nodes[node_idx].covered_length = \
@ -99,14 +106,9 @@ Unit TreeNode::segment_length() {
return right_coord - left_coord; return right_coord - left_coord;
} }
bool TreeNode::covered() {
return coverage > 0;
}
bool SegmentTree::is_leaf(Index node_idx) { bool SegmentTree::is_leaf(Index node_idx) {
return node_idx >= _num_meta_nodes; return node_idx > _num_meta_nodes;
} }
#endif //PROG_SEGMENT_TREE_H #endif //PROG_SEGMENT_TREE_H