void Graph::dijkstra_shortest_path(int root, bool isTerminateAsFound){
//<length nodeid > tricky nodes[i]为节点i在heap中的指针
MinBinaryHeap<int, int > q; //优先队列
vector <BinaryHeapNode<int, int >*> nodes(n);
int min,w; //min 最小权值对应的节点id, w为与min相连的节点id
for (int i = 0; i < n; ++i){
distance[i] = POSTIVE_MAXINT; parent[i] = -1;
if ( i == root ) { distance[i] = 0; parent[i] = i; }
nodes[i] = q.insert(distance[i],i);
}
while(!q.empty()){
min = q.minimum()->data();
if (isTerminateAsFound && min==dest){ //必须等到dest出优先队列才能结束，因为以后都不可能对其松弛
break;
}
if (q.minimum()->key() == POSTIVE_MAXINT){ break; } //后面的都是其他森林，不需要遍历
q.removeMinimum(); nodes[min] = NULL;
//开始更新和u相连的边 relax
list<Node>::iterator itr = linktable[min].begin();
while(itr != linktable[min].end()){
w = itr->id;
if (nodes[w] != NULL) //未被选中加入S
{
if (distance[min]+itr->weight < distance[w]) //relax
{
q.decreaseKey(nodes[w], distance[min]+itr->weight);
distance[w] = distance[min]+itr->weight;
parent[w] = min;
}
}
++itr;
}
}
}
void Graph::dijkstra_without_pass_other_mustpass_nodes(int root){
//<length nodeid > tricky nodes[i]为节点i在heap中的指针
MinBinaryHeap<int, int > q; //优先队列
vector <BinaryHeapNode<int, int >*> nodes(n);
int min,w; //min 最小权值对应的节点id, w为与min相连的节点id
for (int i = 0; i < n; ++i){
distance[i] = POSTIVE_MAXINT; parent[i] = -1;
if ( i == root ) { distance[i] = 0; parent[i] = i; }
nodes[i] = q.insert(distance[i],i);
}
while(!q.empty()){
min = q.minimum()->data();
// if (min==end) break; //必须等到end出优先队列才能结束，因为以后都不可能对其松弛
if (q.minimum()->key() == POSTIVE_MAXINT){ break; } //后面的都是其他森林，不需要遍历
q.removeMinimum(); nodes[min] = NULL;
//除root以外其他必过节点成为黑洞，没有出边,不帮助松弛
if ((min != root )&&(allmustpass.find(min) != allmustpass.end())) continue;
//开始更新和u相连的边 relax
list<Node>::iterator itr = linktable[min].begin();
while(itr != linktable[min].end()){
w = itr->id;
if (nodes[w] != NULL){ //未被选中加入S
if (distance[min]+itr->weight < distance[w]){ //relax
q.decreaseKey(nodes[w], distance[min]+itr->weight);
distance[w] = distance[min]+itr->weight;
parent[w] = min;
}
}
++itr;
}
}
}
bool test_random(int numItems) {
MinBinaryHeap h;
Container ** nodePointers = new Container * [numItems];
IntegerData ** values = new IntegerData * [numItems];
bool failed = false;
int i;
for (i = 0; i < numItems; i++) {
// need to be careful not to work with data that is near integer max or min value
values[i] = new IntegerData(rand() % numItems);
nodePointers[i] = h.insert(values[i]);
}
failed = false;
for (i = 0; i < numItems; i++) {
// need to be careful not to work with data that is near integer max or min value
// because if we subtract from min or add to max we get overflow (undefined behavior)
if (i % 2 == 0) {
values[i]->value -= rand() % numItems;
h.decreaseKey(nodePointers[i]);
}
else {
values[i]->value += rand() % numItems;
h.increaseKey(nodePointers[i]);
}
}
IntegerData * x = (IntegerData*)h.deleteMin();
int lastValue = x->value;
delete x;
for(i = 1; i < numItems; i++ ) {
x = (IntegerData*)h.deleteMin();
if( x->value < lastValue ) {
cout << "Oops! " << x->value << " is not >= " << lastValue << endl;
failed = true;
}
lastValue = x->value;
delete x;
}
if (failed) {
cout << "random test failed" << endl;
}
else {
cout << "random test successful" << endl;
}
delete [] nodePointers;
delete [] values;
return failed;
}
bool test_increase_decreaseKey(int numItems) {
MinBinaryHeap h;
Container ** nodePointers = new Container * [numItems];
IntegerData ** values = new IntegerData * [numItems];
bool failed = false;
int i;
for (i = 0; i < numItems; i++) {
values[i] = new IntegerData(i);
nodePointers[i] = h.insert(values[i]);
}
failed = false;
for (i = 0; i < numItems; i++) {
// decrease all the even ones by 1, increase all the odd ones by 9998
// should result in the sequence -1, 1, 3, ..., 9995, 9997, (odds + 9998)=9999, 10001...
if (i % 2 == 0) {
values[i]->value--;
h.decreaseKey(nodePointers[i]);
}
else {
values[i]->value+=9998;
h.increaseKey(nodePointers[i]);
}
}
for(i = 0; i < numItems; i++ ) {
IntegerData * x = (IntegerData*)h.deleteMin();
if( x->value != (i*2-1) ) {
cout << "Oops! " << (i*2-1) << " != " << x->value << endl;
failed = true;
}
delete x;
}
if (failed) {
cout << "decreaseKey evens/increaseKey odds 0:9999 failed" << endl;
}
else {
cout << "decreaseKey evens/increaseKey odds 0:9999 successful" << endl;
}
delete [] nodePointers;
delete [] values;
return failed;
}