leecode更新

Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/listnode/LC_83_DeleteDuplicates.java

@@ -0,0 +1,59 @@
+package com.markilue.leecode.hot100.interviewHot.listnode;
+
+import com.markilue.leecode.listnode.ListNode;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.hot100.interviewHot.listnode
+ *@Author: markilue
+ *@CreateTime: 2023-05-11  11:26
+ *@Description: TODO  力扣83  删除排序链表中的重复元素:重复的留一个
+ *@Version: 1.0
+ */
+public class LC_83_DeleteDuplicates {
+
+
+    //一个一个删
+    public ListNode deleteDuplicates(ListNode head) {
+        if (head == null) {
+            return head;
+        }
+        ListNode fake = new ListNode(-101);
+        fake.next = head;
+        ListNode cur = fake;
+
+        while (cur.next != null) {
+            if (cur.val == cur.next.val) {
+                cur.next = cur.next.next;
+            } else {
+                cur = cur.next;
+            }
+        }
+
+        return fake.next;
+
+    }
+
+
+    //找到重复的,连环删除一系列(通用)
+    public ListNode deleteDuplicates1(ListNode head) {
+        if (head == null) {
+            return head;
+        }
+        ListNode fake = new ListNode(-101);
+        fake.next = head;
+        ListNode cur = fake;
+        while (cur.next != null) {
+            if (cur.val == cur.next.val) {
+                ListNode temp = cur.next;
+                while (temp.next != null && temp.val == temp.next.val) {
+                    temp = temp.next;
+                }
+                cur.next = temp.next;
+            } else {
+                cur = cur.next;
+            }
+        }
+        return fake.next;
+    }
+}

Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/listnode/LC_84_DeleteDuplicatesII.java

@@ -0,0 +1,33 @@
+package com.markilue.leecode.hot100.interviewHot.listnode;
+
+import com.markilue.leecode.listnode.ListNode;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.hot100.interviewHot.listnode
+ *@Author: markilue
+ *@CreateTime: 2023-05-11  11:38
+ *@Description: TODO 力扣82  删除排序链表中的重复元素II:重复全删
+ *@Version: 1.0
+ */
+public class LC_84_DeleteDuplicatesII {
+
+    public ListNode deleteDuplicates(ListNode head) {
+        ListNode fake = new ListNode(-101);
+        fake.next = head;
+        ListNode cur = fake;
+
+        while (cur != null && cur.next != null && cur.next.next != null) {
+            if (cur.next.val == cur.next.next.val) {
+                ListNode temp = cur.next;
+                while (temp.next != null && temp.val == temp.next.val) {
+                    temp = temp.next;
+                }
+                cur.next = temp.next;
+            } else {
+                cur = cur.next;
+            }
+        }
+        return fake.next;
+    }
+}

Leecode/src/main/java/com/markilue/leecode/hot100/second/T23_42_Trap.java

@@ -79,4 +79,49 @@ public class T23_42_Trap {
         return result;
 
     }
+
+    //二刷:使用单调栈法
+    public int trap2(int[] height) {
+        LinkedList<Integer> stack = new LinkedList<>();
+        int result = 0;
+
+        for (int i = 0; i < height.length; i++) {
+            while (!stack.isEmpty() && height[stack.peek()] < height[i]) {
+                Integer top = stack.pop();
+                if (stack.isEmpty()) {
+                    continue;//stack必须有左边的元素才能计算接雨水量
+                }
+                Integer left = stack.peek();
+                result += (i - left - 1) * (Math.min(height[i], height[left]) - height[top]);//宽*高
+            }
+            stack.push(i);
+        }
+
+        return result;
+
+    }
+
+    //二刷:双指针法
+    public int trap3(int[] height) {
+        int left = 0;
+        int right = height.length - 1;
+        int leftMax = height[left];
+        int rightMax = height[right];
+        int result = 0;
+
+        while (left < right) {
+            leftMax = Math.max(leftMax, height[left]);
+            rightMax = Math.max(rightMax, height[right]);
+            if (leftMax < rightMax) {
+                //左边一定能积水
+                result += (leftMax - height[left]);
+                left++;
+            } else {
+                result += (rightMax - height[right]);
+                right--;
+            }
+        }
+        return result;
+
+    }
 }

Leecode/src/main/java/com/markilue/leecode/hot100/second/T34_75_SortColors.java

@@ -21,7 +21,7 @@ public class T34_75_SortColors {
     @Test
     public void test() {
         int[] nums = {2, 0, 2, 1, 1, 0};
-        sortColors(nums);
+        sortColors1(nums);
         System.out.println(Arrays.toString(nums));
     }
 
@@ -50,4 +50,29 @@ public class T34_75_SortColors {
         nums[i] = nums[j];
         nums[j] = temp;
     }
+
+
+    //二刷:遇上1就直接交换,遇上0就先交换，在判断要不要和1换
+    public void sortColors1(int[] nums) {
+
+        int index0 = 0;
+        int index1 = 0;
+
+        for (int i = 0; i < nums.length; i++) {
+            if (nums[i] == 0) {
+                swap(nums, i, index0);
+                //判断是不是把1给交换到后面了
+                if (index0 < index1) {
+                    //把1交换到后面了,交换回来
+                    swap(nums, i, index1);
+                }
+                index0++;
+                index1++;
+            } else if (nums[i] == 1) {
+                swap(nums, i, index1);
+                index1++;
+            }
+        }
+
+    }
 }

Leecode/src/main/java/com/markilue/leecode/hot100/second/T56_148_SortList.java

@@ -0,0 +1,51 @@
+package com.markilue.leecode.hot100.second;
+
+import com.markilue.leecode.listnode.ListNode;
+import com.markilue.leecode.listnode.ListNodeUtils;
+import org.junit.Test;
+
+/**
+ *@BelongsProject: Leecode
+ *@BelongsPackage: com.markilue.leecode.hot100.second
+ *@Author: markilue
+ *@CreateTime: 2023-05-11  11:00
+ *@Description: TODO  力扣148  排序链表:
+ *@Version: 1.0
+ */
+public class T56_148_SortList {
+
+    @Test
+    public void test() {
+        ListNode root = ListNodeUtils.build(new int[]{4, 2, 1, 3});
+        sortList(root);
+    }
+
+    //利用count直接构造:提前记录每一个数出现的次数，直接构造
+    public ListNode sortList(ListNode head) {
+
+        int min = Integer.MAX_VALUE;
+        int max = Integer.MIN_VALUE;
+        ListNode cur = head;
+        while (cur != null) {
+            if (cur.val < min) min = cur.val;
+            if (cur.val > max) max = cur.val;
+            cur = cur.next;
+        }
+        int[] count = new int[max - min + 1];
+        ListNode temp = head;
+        while (temp != null) {
+            count[temp.val - min]++;
+            temp = temp.next;
+        }
+        ListNode fake = new ListNode();
+        ListNode tt = fake;
+        for (int i = 0; i < count.length; i++) {
+            int num = count[i];
+            while (num-- > 0) {
+                tt.next = new ListNode(i + min);
+                tt = tt.next;
+            }
+        }
+        return fake.next;
+    }
+}