modify code on class

src/class10_16/Code01_BFS.java

@@ -1,4 +1,4 @@
-package class10;
+package class10_16;
 
 import java.util.HashSet;
 import java.util.LinkedList;

src/class10_16/Code02_DFS.java

@@ -1,4 +1,4 @@
-package class10;
+package class10_16;
 
 import java.util.HashSet;
 import java.util.Stack;

src/class10_16/Code03_TopologicalOrderBFS.java

@@ -1,4 +1,4 @@
-package class10;
+package class10_16;
 
 import java.util.ArrayList;
 import java.util.HashMap;

src/class10_16/Code03_TopologicalOrderDFS1.java

@@ -1,4 +1,4 @@
-package class10;
+package class10_16;
 
 import java.util.ArrayList;
 import java.util.Comparator;

src/class10_16/Code03_TopologicalOrderDFS2.java

@@ -1,4 +1,4 @@
-package class10;
+package class10_16;
 
 import java.util.ArrayList;
 import java.util.Comparator;

src/class10_16/Code03_TopologySort.java

@@ -1,4 +1,4 @@
-package class10;
+package class10_16;
 
 import java.util.ArrayList;
 import java.util.HashMap;

src/class10_16/Code04_Kruskal.java

@@ -1,4 +1,4 @@
-package class10;
+package class10_16;
 
 import java.util.Collection;
 import java.util.Comparator;

src/class10_16/Code05_Prim.java

@@ -1,4 +1,4 @@
-package class10;
+package class10_16;
 
 import java.util.Comparator;
 import java.util.HashSet;

src/class10_16/Code06_Dijkstra.java

@@ -1,4 +1,4 @@
-package class10;
+package class10_16;
 
 import java.util.HashMap;
 import java.util.HashSet;

src/class10_16/Edge.java

@@ -1,4 +1,4 @@
-package class10;
+package class10_16;
 
 public class Edge {
 	public int weight;

src/class10_16/Graph.java

@@ -1,4 +1,4 @@
-package class10;
+package class10_16;
 
 import java.util.HashMap;
 import java.util.HashSet;

src/class10_16/GraphGenerator.java

@@ -1,4 +1,4 @@
-package class10;
+package class10_16;
 
 public class GraphGenerator {
 

src/class10_16/Node.java

@@ -1,4 +1,4 @@
-package class10;
+package class10_16;
 
 import java.util.ArrayList;
 

src/class10_17/Code01_Dijkstra.java

@@ -0,0 +1,160 @@
+package class10_17;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map.Entry;
+
+// no negative weight
+public class Code01_Dijkstra {
+
+	public static HashMap<Node, Integer> dijkstra1(Node from) {
+		HashMap<Node, Integer> distanceMap = new HashMap<>();
+		distanceMap.put(from, 0);
+		// 打过对号的点
+		HashSet<Node> selectedNodes = new HashSet<>();
+		Node minNode = getMinDistanceAndUnselectedNode(distanceMap, selectedNodes);
+		while (minNode != null) {
+			//  原始点  ->  minNode(跳转点)   最小距离distance
+			int distance = distanceMap.get(minNode);
+			for (Edge edge : minNode.edges) {
+				Node toNode = edge.to;
+				if (!distanceMap.containsKey(toNode)) {
+					distanceMap.put(toNode, distance + edge.weight);
+				} else { // toNode 
+					distanceMap.put(edge.to, Math.min(distanceMap.get(toNode), distance + edge.weight));
+				}
+			}
+			selectedNodes.add(minNode);
+			minNode = getMinDistanceAndUnselectedNode(distanceMap, selectedNodes);
+		}
+		return distanceMap;
+	}
+
+	public static Node getMinDistanceAndUnselectedNode(HashMap<Node, Integer> distanceMap, HashSet<Node> touchedNodes) {
+		Node minNode = null;
+		int minDistance = Integer.MAX_VALUE;
+		for (Entry<Node, Integer> entry : distanceMap.entrySet()) {
+			Node node = entry.getKey();
+			int distance = entry.getValue();
+			if (!touchedNodes.contains(node) && distance < minDistance) {
+				minNode = node;
+				minDistance = distance;
+			}
+		}
+		return minNode;
+	}
+
+	public static class NodeRecord {
+		public Node node;
+		public int distance;
+
+		public NodeRecord(Node node, int distance) {
+			this.node = node;
+			this.distance = distance;
+		}
+	}
+
+	public static class NodeHeap {
+		private Node[] nodes; // 实际的堆结构
+		// key 某一个node， value 上面堆中的位置
+		private HashMap<Node, Integer> heapIndexMap;
+		// key 某一个节点， value 从源节点出发到该节点的目前最小距离
+		private HashMap<Node, Integer> distanceMap;
+		private int size; // 堆上有多少个点
+
+		public NodeHeap(int size) {
+			nodes = new Node[size];
+			heapIndexMap = new HashMap<>();
+			distanceMap = new HashMap<>();
+			size = 0;
+		}
+
+		public boolean isEmpty() {
+			return size == 0;
+		}
+
+		// 有一个点叫node，现在发现了一个从源节点出发到达node的距离为distance
+		// 判断要不要更新，如果需要的话，就更新
+		public void addOrUpdateOrIgnore(Node node, int distance) {
+			if (inHeap(node)) {
+				distanceMap.put(node, Math.min(distanceMap.get(node), distance));
+				insertHeapify(node, heapIndexMap.get(node));
+			}
+			if (!isEntered(node)) {
+				nodes[size] = node;
+				heapIndexMap.put(node, size);
+				distanceMap.put(node, distance);
+				insertHeapify(node, size++);
+			}
+		}
+
+		public NodeRecord pop() {
+			NodeRecord nodeRecord = new NodeRecord(nodes[0], distanceMap.get(nodes[0]));
+			swap(0, size - 1);
+			heapIndexMap.put(nodes[size - 1], -1);
+			distanceMap.remove(nodes[size - 1]);
+			// free C++同学还要把原本堆顶节点析构，对java同学不必
+			nodes[size - 1] = null;
+			heapify(0, --size);
+			return nodeRecord;
+		}
+
+		private void insertHeapify(Node node, int index) {
+			while (distanceMap.get(nodes[index]) < distanceMap.get(nodes[(index - 1) / 2])) {
+				swap(index, (index - 1) / 2);
+				index = (index - 1) / 2;
+			}
+		}
+
+		private void heapify(int index, int size) {
+			int left = index * 2 + 1;
+			while (left < size) {
+				int smallest = left + 1 < size && distanceMap.get(nodes[left + 1]) < distanceMap.get(nodes[left])
+						? left + 1
+						: left;
+				smallest = distanceMap.get(nodes[smallest]) < distanceMap.get(nodes[index]) ? smallest : index;
+				if (smallest == index) {
+					break;
+				}
+				swap(smallest, index);
+				index = smallest;
+				left = index * 2 + 1;
+			}
+		}
+
+		private boolean isEntered(Node node) {
+			return heapIndexMap.containsKey(node);
+		}
+
+		private boolean inHeap(Node node) {
+			return isEntered(node) && heapIndexMap.get(node) != -1;
+		}
+
+		private void swap(int index1, int index2) {
+			heapIndexMap.put(nodes[index1], index2);
+			heapIndexMap.put(nodes[index2], index1);
+			Node tmp = nodes[index1];
+			nodes[index1] = nodes[index2];
+			nodes[index2] = tmp;
+		}
+	}
+
+	// 改进后的dijkstra算法
+	// 从head出发，所有head能到达的节点，生成到达每个节点的最小路径记录并返回
+	public static HashMap<Node, Integer> dijkstra2(Node head, int size) {
+		NodeHeap nodeHeap = new NodeHeap(size);
+		nodeHeap.addOrUpdateOrIgnore(head, 0);
+		HashMap<Node, Integer> result = new HashMap<>();
+		while (!nodeHeap.isEmpty()) {
+			NodeRecord record = nodeHeap.pop();
+			Node cur = record.node;
+			int distance = record.distance;
+			for (Edge edge : cur.edges) {
+				nodeHeap.addOrUpdateOrIgnore(edge.to, edge.weight + distance);
+			}
+			result.put(cur, distance);
+		}
+		return result;
+	}
+
+}

src/class10_17/Edge.java

@@ -0,0 +1,14 @@
+package class10_17;
+
+public class Edge {
+	public int weight;
+	public Node from;
+	public Node to;
+
+	public Edge(int weight, Node from, Node to) {
+		this.weight = weight;
+		this.from = from;
+		this.to = to;
+	}
+
+}

src/class10_17/Graph.java

@@ -0,0 +1,14 @@
+package class10_17;
+
+import java.util.HashMap;
+import java.util.HashSet;
+
+public class Graph {
+	public HashMap<Integer, Node> nodes;
+	public HashSet<Edge> edges;
+	
+	public Graph() {
+		nodes = new HashMap<>();
+		edges = new HashSet<>();
+	}
+}

src/class10_17/Node.java

@@ -0,0 +1,20 @@
+package class10_17;
+
+import java.util.ArrayList;
+
+// 点结构的描述
+public class Node {
+	public int value;
+	public int in;
+	public int out;
+	public ArrayList<Node> nexts;
+	public ArrayList<Edge> edges;
+
+	public Node(int value) {
+		this.value = value;
+		in = 0;
+		out = 0;
+		nexts = new ArrayList<>();
+		edges = new ArrayList<>();
+	}
+}

src/class11_17/Code01_Hanoi.java

@@ -1,4 +1,4 @@
-package class11;
+package class11_17;
 
 import java.util.Stack;
 

src/class11_17/Code02_PrintAllSubsquences.java

@@ -1,4 +1,4 @@
-package class11;
+package class11_17;
 
 import java.util.ArrayList;
 import java.util.HashSet;

src/class11_17/Code03_PrintAllPermutations.java

@@ -1,4 +1,4 @@
-package class11;
+package class11_17;
 
 import java.util.ArrayList;
 import java.util.List;

src/class11_17/Code04_ReverseStackUsingRecursive.java

@@ -1,4 +1,4 @@
-package class11;
+package class11_17;
 
 import java.util.Stack;
 

src/class11_17/Code06_ConvertToLetterString.java

@@ -1,4 +1,4 @@
-package class11;
+package class11_17;
 
 public class Code06_ConvertToLetterString {
 

src/class11_17/Code07_Knapsack.java

@@ -1,4 +1,4 @@
-package class11;
+package class11_17;
 
 public class Code07_Knapsack {
 

src/class11_17/Code08_CardsInLine.java

@@ -1,4 +1,4 @@
-package class11;
+package class11_17;
 
 public class Code08_CardsInLine {
 

src/class11_17/Code09_NQueens.java

@@ -1,4 +1,4 @@
-package class11;
+package class11_17;
 
 public class Code09_NQueens {