modify code

MCA算法突击课/第03期/mca_02/Code01_CoverMax.java

@@ -5,11 +5,32 @@ import java.util.PriorityQueue;
 
 public class Code01_CoverMax {
 
+	public static void main(String[] args) {
+		// 堆
+		// log N
+		PriorityQueue<Integer> heap = new PriorityQueue<>((a, b) -> a - b);
+		heap.add(8);
+		heap.add(2);
+		heap.add(3);
+		heap.add(9);
+		heap.add(4);
+		heap.add(4);
+		while (!heap.isEmpty()) {
+			System.out.println(heap.poll());
+		}
+	}
+
 	public static int maxCover(int[][] m) {
+		// m = [ [4, 7], [3, 6], [1, 5] , [2, 9] ]
+		// 开始位置排序！
+		// m = [ [1, 5], [2, 9], [3, 6] , [4, 7] ]
 		Arrays.sort(m, (a, b) -> (a[0] - b[0]));
+		// 小根堆！建立！
 		PriorityQueue<Integer> heap = new PriorityQueue<>();
 		int max = 0;
 		for (int[] line : m) {
+			// line : line[0]  line[1]
+			// <= line[0]
 			while (!heap.isEmpty() && heap.peek() <= line[0]) {
 				heap.poll();
 			}

MCA算法突击课/第03期/mca_02/Code02_LessMoneySplitGold.java

@@ -5,12 +5,15 @@ import java.util.PriorityQueue;
 public class Code02_LessMoneySplitGold {
 
 	public static int lessMoney(int[] arr) {
+		// 小根堆！
 		PriorityQueue<Integer> pQ = new PriorityQueue<>();
-		for (int i = 0; i < arr.length; i++) {
-			pQ.add(arr[i]);
+		// 所有数字扔到小根堆里
+		for (int num : arr) {
+			pQ.add(num);
 		}
 		int sum = 0;
 		int cur = 0;
+		// 小根堆只剩一个数字的时候停！
 		while (pQ.size() > 1) {
 			cur = pQ.poll() + pQ.poll();
 			sum += cur;

MCA算法突击课/第03期/mca_02/Code05_AddTwoNumbers.java

@@ -21,7 +21,9 @@ public class Code05_AddTwoNumbers {
 	public static ListNode addTwoNumbers(ListNode head1, ListNode head2) {
 		int len1 = listLength(head1);
 		int len2 = listLength(head2);
+		// 长链表 找到l
 		ListNode l = len1 >= len2 ? head1 : head2;
+		// 短链表 找到s
 		ListNode s = l == head1 ? head2 : head1;
 		ListNode curL = l;
 		ListNode curS = s;
@@ -36,6 +38,7 @@ public class Code05_AddTwoNumbers {
 			curL = curL.next;
 			curS = curS.next;
 		}
+		// 短链表没了
 		while (curL != null) {
 			curNum = curL.val + carry;
 			curL.val = (curNum % 10);
@@ -43,6 +46,7 @@ public class Code05_AddTwoNumbers {
 			last = curL;
 			curL = curL.next;
 		}
+		// 长链表没了
 		if (carry != 0) {
 			last.next = new ListNode(1);
 		}

MCA算法突击课/第03期/mca_02/Code07_CopyListWithRandom.java

@@ -45,8 +45,8 @@ public class Code07_CopyListWithRandom {
 		Node cur = head;
 		Node next = null;
 		// 1 -> 2 -> 3 -> null
-		// 1 -> 1' -> 2 -> 2' -> 3 -> 3'
 		while (cur != null) {
+			// 1 -> 1' -> 2(next) -> ...
 			next = cur.next;
 			cur.next = new Node(cur.val);
 			cur.next.next = next;
@@ -54,11 +54,15 @@ public class Code07_CopyListWithRandom {
 		}
 		cur = head;
 		Node copy = null;
-		// 1 1' 2 2' 3 3'
+		// 1 1' 2 2' 3 3' null
 		// 依次设置 1' 2' 3' random指针
 		while (cur != null) {
+			// 1 -> 1' -> 2(next)
 			next = cur.next.next;
+			// cur  1
+			// copy 1'
 			copy = cur.next;
+			// 1'.random = 
 			copy.random = cur.random != null ? cur.random.next : null;
 			cur = next;
 		}
@@ -67,9 +71,14 @@ public class Code07_CopyListWithRandom {
 		// 老 新 混在一起，next方向上，random正确
 		// next方向上，把新老链表分离
 		while (cur != null) {
+			// 1 -> 1' -> 2(next) -> 2'
 			next = cur.next.next;
+			// cur  1
+			// copy 1'
 			copy = cur.next;
+			// 1 -> 2
 			cur.next = next;
+			// 1' -next->
 			copy.next = next != null ? next.next : null;
 			cur = next;
 		}

MCA算法突击课/第03期/mca_02/Code08_ReverseNodesInKGroup.java

@@ -1,59 +0,0 @@
-
-
-package 第03期.mca_02;
-
-// 测试链接：https://leetcode.com/problems/reverse-nodes-in-k-group/
-public class Code08_ReverseNodesInKGroup {
-
-	// 不要提交这个类
-	public static class ListNode {
-		public int val;
-		public ListNode next;
-	}
-
-	public static ListNode reverseKGroup(ListNode head, int k) {
-		ListNode start = head;
-		ListNode end = getKGroupEnd(start, k);
-		if (end == null) {
-			return head;
-		}
-		// 第一组凑齐了！
-		head = end;
-		reverse(start, end);
-		// 上一组的结尾节点
-		ListNode lastEnd = start;
-		while (lastEnd.next != null) {
-			start = lastEnd.next;
-			end = getKGroupEnd(start, k);
-			if (end == null) {
-				return head;
-			}
-			reverse(start, end);
-			lastEnd.next = end;
-			lastEnd = start;
-		}
-		return head;
-	}
-
-	public static ListNode getKGroupEnd(ListNode start, int k) {
-		while (--k != 0 && start != null) {
-			start = start.next;
-		}
-		return start;
-	}
-
-	public static void reverse(ListNode start, ListNode end) {
-		end = end.next;
-		ListNode pre = null;
-		ListNode cur = start;
-		ListNode next = null;
-		while (cur != end) {
-			next = cur.next;
-			cur.next = pre;
-			pre = cur;
-			cur = next;
-		}
-		start.next = end;
-	}
-
-}

MCA算法突击课/第03期/mca_02/Code09_MergeKSortedLists.java

@@ -1,52 +0,0 @@
-package 第03期.mca_02;
-
-import java.util.Comparator;
-import java.util.PriorityQueue;
-
-// 测试链接：https://leetcode.com/problems/merge-k-sorted-lists/
-public class Code09_MergeKSortedLists {
-
-	public static class ListNode {
-		public int val;
-		public ListNode next;
-	}
-
-	public static class ListNodeComparator implements Comparator<ListNode> {
-
-		@Override
-		public int compare(ListNode o1, ListNode o2) {
-			return o1.val - o2.val; 
-		}
-
-	}
-
-	public static ListNode mergeKLists(ListNode[] lists) {
-		if (lists == null) {
-			return null;
-		}
-		PriorityQueue<ListNode> heap = new PriorityQueue<>(new ListNodeComparator());
-		for (int i = 0; i < lists.length; i++) {
-			if (lists[i] != null) {
-				heap.add(lists[i]);
-			}
-		}
-		if (heap.isEmpty()) {
-			return null;
-		}
-		ListNode head = heap.poll();
-		ListNode pre = head;
-		if (pre.next != null) {
-			heap.add(pre.next);
-		}
-		while (!heap.isEmpty()) {
-			ListNode cur = heap.poll();
-			pre.next = cur;
-			pre = cur;
-			if (cur.next != null) {
-				heap.add(cur.next);
-			}
-		}
-		return head;
-	}
-
-}

体系学习班/class03/Code01_ReverseList.java

@@ -208,7 +208,7 @@ public class Code01_ReverseList {
 
 			DoubleNode node4 = generateRandomDoubleList(len, value);
 			List<Integer> list4 = getDoubleListOriginOrder(node4);
-			node4 = reverseDoubleList(node4);
+			node4 = testReverseDoubleList(node4);
 			if (!checkDoubleListReverse(list4, node4)) {
 				System.out.println("Oops4!");
 			}