diff --git a/Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/listnode/LC_83_DeleteDuplicates.java b/Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/listnode/LC_83_DeleteDuplicates.java new file mode 100644 index 0000000..d9d9636 --- /dev/null +++ b/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; + } +} diff --git a/Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/listnode/LC_84_DeleteDuplicatesII.java b/Leecode/src/main/java/com/markilue/leecode/hot100/interviewHot/listnode/LC_84_DeleteDuplicatesII.java new file mode 100644 index 0000000..2ee7ea2 --- /dev/null +++ b/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; + } +} diff --git a/Leecode/src/main/java/com/markilue/leecode/hot100/second/T23_42_Trap.java b/Leecode/src/main/java/com/markilue/leecode/hot100/second/T23_42_Trap.java index 91a2e93..2595657 100644 --- a/Leecode/src/main/java/com/markilue/leecode/hot100/second/T23_42_Trap.java +++ b/Leecode/src/main/java/com/markilue/leecode/hot100/second/T23_42_Trap.java @@ -70,7 +70,7 @@ public class T23_42_Trap { } Integer left = stack.peek(); int curWidth = i - left - 1; - int curHeight = Math.min(height[left], height[i])-height[top]; + int curHeight = Math.min(height[left], height[i]) - height[top]; result += curHeight * curWidth; } stack.push(i); @@ -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 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; + + } } diff --git a/Leecode/src/main/java/com/markilue/leecode/hot100/second/T34_75_SortColors.java b/Leecode/src/main/java/com/markilue/leecode/hot100/second/T34_75_SortColors.java index 04a8fb2..7ae21d8 100644 --- a/Leecode/src/main/java/com/markilue/leecode/hot100/second/T34_75_SortColors.java +++ b/Leecode/src/main/java/com/markilue/leecode/hot100/second/T34_75_SortColors.java @@ -20,8 +20,8 @@ public class T34_75_SortColors { @Test public void test() { - int[] nums = {2,0,2,1,1,0}; - sortColors(nums); + int[] nums = {2, 0, 2, 1, 1, 0}; + 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++; + } + } + + } } diff --git a/Leecode/src/main/java/com/markilue/leecode/hot100/second/T56_148_SortList.java b/Leecode/src/main/java/com/markilue/leecode/hot100/second/T56_148_SortList.java new file mode 100644 index 0000000..9182eda --- /dev/null +++ b/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; + } +}