diff --git a/src/class10/Code03_TopologicalOrderDFS.java b/src/class10/Code03_TopologicalOrderDFS1.java similarity index 97% rename from src/class10/Code03_TopologicalOrderDFS.java rename to src/class10/Code03_TopologicalOrderDFS1.java index d15fbe6..9514606 100644 --- a/src/class10/Code03_TopologicalOrderDFS.java +++ b/src/class10/Code03_TopologicalOrderDFS1.java @@ -5,7 +5,7 @@ import java.util.Comparator; import java.util.HashMap; // OJ链接：https://www.lintcode.com/problem/topological-sorting -public class Code03_TopologicalOrderDFS { +public class Code03_TopologicalOrderDFS1 { // 不要提交这个类 public static class DirectedGraphNode { diff --git a/src/class10/Code03_TopologicalOrderDFS2.java b/src/class10/Code03_TopologicalOrderDFS2.java new file mode 100644 index 0000000..7cf5f79 --- /dev/null +++ b/src/class10/Code03_TopologicalOrderDFS2.java @@ -0,0 +1,70 @@ +package class10; + +import java.util.ArrayList; +import java.util.Comparator; +import java.util.HashMap; + +// OJ链接：https://www.lintcode.com/problem/topological-sorting +public class Code03_TopologicalOrderDFS2 { + + // 不要提交这个类 + public static class DirectedGraphNode { + public int label; + public ArrayList neighbors; + + public DirectedGraphNode(int x) { + label = x; + neighbors = new ArrayList(); + } + } + + // 提交下面的 + public static class Record { + public DirectedGraphNode node; + public long nodes; + + public Record(DirectedGraphNode n, long o) { + node = n; + nodes = o; + } + } + + public static class MyComparator implements Comparator { + + @Override + public int compare(Record o1, Record o2) { + return o1.nodes == o2.nodes ? 0 : (o1.nodes > o2.nodes ? -1 : 1); + } + } + + public static ArrayList topSort(ArrayList graph) { + HashMap order = new HashMap<>(); + for (DirectedGraphNode cur : graph) { + f(cur, order); + } + ArrayList recordArr = new ArrayList<>(); + for (Record r : order.values()) { + recordArr.add(r); + } + recordArr.sort(new MyComparator()); + ArrayList ans = new ArrayList(); + for (Record r : recordArr) { + ans.add(r.node); + } + return ans; + } + + public static Record f(DirectedGraphNode cur, HashMap order) { + if (order.containsKey(cur)) { + return order.get(cur); + } + long nodes = 0; + for (DirectedGraphNode next : cur.neighbors) { + nodes += f(next, order).nodes; + } + Record ans = new Record(cur, nodes + 1); + order.put(cur, ans); + return ans; + } + +} diff --git a/src/class10/Code03_TopologySort.java b/src/class10/Code03_TopologySort.java index 43533de..2c79e2f 100644 --- a/src/class10/Code03_TopologySort.java +++ b/src/class10/Code03_TopologySort.java @@ -10,20 +10,14 @@ public class Code03_TopologySort { // directed graph and no loop public static List sortedTopology(Graph graph) { - // key：某一个node - // value：剩余的入度 HashMap inMap = new HashMap<>(); - // 剩余入度为0的点，才能进这个队列 Queue zeroInQueue = new LinkedList<>(); - - for (Node node : graph.nodes.values()) { inMap.put(node, node.in); if (node.in == 0) { zeroInQueue.add(node); } } - // 拓扑排序的结果，依次加入result List result = new ArrayList<>(); while (!zeroInQueue.isEmpty()) { Node cur = zeroInQueue.poll(); diff --git a/src/class10/Code06_Dijkstra.java b/src/class10/Code06_Dijkstra.java index b561cf3..b20d01d 100644 --- a/src/class10/Code06_Dijkstra.java +++ b/src/class10/Code06_Dijkstra.java @@ -8,15 +8,9 @@ import java.util.Map.Entry; public class Code06_Dijkstra { public static HashMap dijkstra1(Node from) { - // 从head出发到所有点的最小距离 - // key : 从head出发到达key - // value : 从head出发到达key的最小距离 - // 如果在表中，没有T的记录，含义是从head出发到T这个点的距离为正无穷 HashMap distanceMap = new HashMap<>(); distanceMap.put(from, 0); - // 已经求过距离的节点，存在selectedNodes中，以后再也不碰 HashSet selectedNodes = new HashSet<>(); - // from 0 Node minNode = getMinDistanceAndUnselectedNode(distanceMap, selectedNodes); while (minNode != null) { int distance = distanceMap.get(minNode); @@ -25,8 +19,7 @@ public class Code06_Dijkstra { if (!distanceMap.containsKey(toNode)) { distanceMap.put(toNode, distance + edge.weight); } else { - distanceMap.put(edge.to, - Math.min(distanceMap.get(toNode), distance + edge.weight)); + distanceMap.put(edge.to, Math.min(distanceMap.get(toNode), distance + edge.weight)); } } selectedNodes.add(minNode); @@ -35,9 +28,7 @@ public class Code06_Dijkstra { return distanceMap; } - public static Node getMinDistanceAndUnselectedNode( - HashMap distanceMap, - HashSet touchedNodes) { + public static Node getMinDistanceAndUnselectedNode(HashMap distanceMap, HashSet touchedNodes) { Node minNode = null; int minDistance = Integer.MAX_VALUE; for (Entry entry : distanceMap.entrySet()) { @@ -107,8 +98,7 @@ public class Code06_Dijkstra { } private void insertHeapify(Node node, int index) { - while (distanceMap.get(nodes[index]) - < distanceMap.get(nodes[(index - 1) / 2])) { + while (distanceMap.get(nodes[index]) < distanceMap.get(nodes[(index - 1) / 2])) { swap(index, (index - 1) / 2); index = (index - 1) / 2; } @@ -120,8 +110,7 @@ public class Code06_Dijkstra { 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; + smallest = distanceMap.get(nodes[smallest]) < distanceMap.get(nodes[index]) ? smallest : index; if (smallest == index) { break; } diff --git a/src/class10/Code07_MergeUsers.java b/src/class10/Code07_MergeUsers.java deleted file mode 100644 index 95faab8..0000000 --- a/src/class10/Code07_MergeUsers.java +++ /dev/null @@ -1,118 +0,0 @@ -package class10; - -import java.util.HashMap; -import java.util.List; -import java.util.Stack; - -public class Code07_MergeUsers { - - public static class Node { - V value; - - public Node(V v) { - value = v; - } - } - - public static class UnionSet { - public HashMap> nodes; - public HashMap, Node> parents; - public HashMap, Integer> sizeMap; - - public UnionSet(List values) { - for (V cur : values) { - Node node = new Node<>(cur); - nodes.put(cur, node); - parents.put(node, node); - sizeMap.put(node, 1); - } - } - - // 从点cur开始，一直往上找，找到不能再往上的代表点，返回 - public Node findFather(Node cur) { - Stack> path = new Stack<>(); - while (cur != parents.get(cur)) { - path.push(cur); - cur = parents.get(cur); - } - // cur头节点 - while (!path.isEmpty()) { - parents.put(path.pop(), cur); - } - return cur; - } - - public boolean isSameSet(V a, V b) { - if (!nodes.containsKey(a) || !nodes.containsKey(b)) { - return false; - } - return findFather(nodes.get(a)) == findFather(nodes.get(b)); - } - - public void union(V a, V b) { - if (!nodes.containsKey(a) || !nodes.containsKey(b)) { - return; - } - Node aHead = findFather(nodes.get(a)); - Node bHead = findFather(nodes.get(b)); - if (aHead != bHead) { - int aSetSize = sizeMap.get(aHead); - int bSetSize = sizeMap.get(bHead); - Node big = aSetSize >= bSetSize ? aHead : bHead; - Node small = big == aHead ? bHead : aHead; - parents.put(small, big); - sizeMap.put(big, aSetSize + bSetSize); - sizeMap.remove(small); - } - } - - - public int getSetNum() { - return sizeMap.size(); - } - - } - - public static class User { - public String a; - public String b; - public String c; - - public User(String a, String b, String c) { - this.a = a; - this.b = b; - this.c = c; - } - - } - - // (1,10,13) (2,10,37) (400,500,37) - // 如果两个user，a字段一样、或者b字段一样、或者c字段一样，就认为是一个人 - // 请合并users，返回合并之后的用户数量 - public static int mergeUsers(List users) { - UnionSet unionFind = new UnionSet<>(users); - HashMap mapA = new HashMap<>(); - HashMap mapB = new HashMap<>(); - HashMap mapC = new HashMap<>(); - for(User user : users) { - if(mapA.containsKey(user.a)) { - unionFind.union(user, mapA.get(user.a)); - }else { - mapA.put(user.a, user); - } - if(mapB.containsKey(user.b)) { - unionFind.union(user, mapB.get(user.b)); - }else { - mapB.put(user.b, user); - } - if(mapC.containsKey(user.c)) { - unionFind.union(user, mapC.get(user.c)); - }else { - mapC.put(user.c, user); - } - } - // 向并查集询问，合并之后，还有多少个集合？ - return unionFind.getSetNum(); - } - -}