新增五个LeetCode算法题的解决方案

- 添加了LeetCode12（整数转罗马数字）的解决方案
- 添加了LeetCode13（罗马数字转整数）的解决方案
- 添加了LeetCode57（插入区间）的解决方案
- 添加了LeetCode92（反转链表的一部分）的解决方案
- 添加了LeetCode124（二叉树最大路径和）的解决方案

ForJdk17/src/main/java/cn/whaifree/redo/redo_all_240924/LeetCode12.java

@@ -0,0 +1,40 @@
+package cn.whaifree.redo.redo_all_240924;
+
+import org.junit.Test;
+
+/**
+ * @version 1.0
+ * @Author whai文海
+ * @Date 2024/10/6 11:12
+ * @注释
+ */
+public class LeetCode12 {
+    @Test
+    public void test(){
+        Solution solution = new Solution();
+        String s = solution.intToRoman(1994);
+        System.out.println(s);
+    }
+
+
+    class Solution{
+        // 每个标准-前一个 9 5 4 1
+        int[] nums = new int[] { 1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1 };
+        String[] romans = new String[] { "M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I" };
+        public String intToRoman(int num) {
+            StringBuilder sb = new StringBuilder();
+            while (num > 0) {
+                for (int i = 0; i < nums.length; i++) {
+                    if (num >= nums[i]) {
+                        sb.append(romans[i]);
+                        num -= nums[i];
+                        break;
+                    }
+                }
+                if (num == 0) break;
+            }
+            return sb.toString();
+        }
+
+    }
+}

ForJdk17/src/main/java/cn/whaifree/redo/redo_all_240924/LeetCode124.java

@@ -0,0 +1,33 @@
+package cn.whaifree.redo.redo_all_240924;
+
+import cn.whaifree.leetCode.model.TreeNode;
+
+/**
+ * @version 1.0
+ * @Author whai文海
+ * @Date 2024/10/6 12:22
+ * @注释
+ */
+public class LeetCode124 {
+    class Solution {
+
+        int max = Integer.MIN_VALUE;
+        public int maxPathSum(TreeNode root) {
+            if (root == null) {
+                return 0;
+            }
+            int left = maxPathSum(root.left);
+            if (left < 0) {
+                // 不采纳左边的
+                left = 0;
+            }
+            int right = maxPathSum(root.right);
+            if (right < 0) {
+                right = 0;
+            }
+            max = Math.max(max, left + right + root.val);
+            return Math.max(left, right) + root.val; // 一个节点只能选择一条路，左路或者右路
+        }
+    }
+}
+

ForJdk17/src/main/java/cn/whaifree/redo/redo_all_240924/LeetCode13.java

@@ -0,0 +1,51 @@
+package cn.whaifree.redo.redo_all_240924;
+
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * @version 1.0
+ * @Author whai文海
+ * @Date 2024/10/6 11:32
+ * @注释
+ */
+public class LeetCode13 {
+
+    @Test
+    public void test() {
+        Solution solution = new Solution();
+        System.out.println(solution.romanToInt("MCMXCIV"));
+    }
+
+    class Solution {
+        static Map<Character, Integer> map;
+        static {
+            map = new HashMap<>();
+            map.put('I', 1);
+            map.put('V', 5);
+            map.put('X', 10);
+            map.put('L', 50);
+            map.put('C', 100);
+            map.put('D', 500);
+            map.put('M', 1000);
+        }
+        public int romanToInt(String s) {
+            char[] charArray = s.toCharArray();
+
+            int res = 0;
+            for (int i = s.length() - 1; i >= 0; i--) {
+                char c = charArray[i];
+                Integer v = map.get(c);
+                if (i > 0 && v > map.get(charArray[i - 1])) {
+                    v -= map.get(charArray[i - 1]);
+                    i--;
+                }
+                res += v;
+            }
+            return res;
+        }
+    }
+
+}

ForJdk17/src/main/java/cn/whaifree/redo/redo_all_240924/LeetCode57.java

@@ -0,0 +1,51 @@
+package cn.whaifree.redo.redo_all_240924;
+
+import java.util.Arrays;
+
+/**
+ * @version 1.0
+ * @Author whai文海
+ * @Date 2024/10/6 11:49
+ * @注释
+ */
+public class LeetCode57 {
+
+    class Solution {
+        /**
+         * | |  |  |  |   |
+         *   |       |
+         *
+         * @param intervals
+         * @param newInterval
+         * @return
+         */
+        public int[][] insert(int[][] intervals, int[] newInterval) {
+            int[][] res = new int[intervals.length + 1][2];
+            int i = 0;
+            int index = 0;
+            // 找到newInterval的左边界位置
+            while (intervals[index][0] < newInterval[0]) {
+                res[i++] = intervals[index];
+                index++;
+            }
+            // 此时index的value >= newInterval的起始位置
+
+            // 找到newInterval右边边界位置
+            while (intervals[index][1] <= newInterval[1]) {
+                newInterval[0] = Math.min(newInterval[0], intervals[index][0]);
+                newInterval[1] = Math.max(newInterval[1], intervals[index][1]);
+                index ++;
+            }
+
+            res[i++] = newInterval;
+            // 把newInterval右边界右边的位置全部移动过来
+            while (index < intervals.length) {
+                res[i++] = intervals[index];
+                index++;
+            }
+            return Arrays.copyOf(res, i);
+        }
+    }
+
+
+}

ForJdk17/src/main/java/cn/whaifree/redo/redo_all_240924/LeetCode92.java

@@ -0,0 +1,59 @@
+package cn.whaifree.redo.redo_all_240924;
+
+import cn.whaifree.leetCode.model.ListNode;
+import org.junit.Test;
+
+/**
+ * @version 1.0
+ * @Author whai文海
+ * @Date 2024/10/6 12:07
+ * @注释
+ */
+public class LeetCode92  {
+
+    @Test
+    public void test() {
+        ListNode listNode = ListNode.listNodeFromArray(new int[]{1, 2, 3, 4, 5});
+
+        ListNode listNode1 = new Solution().reverseBetween(listNode, 1, 5);
+        listNode1.printList();
+
+    }
+
+    class Solution {
+        public ListNode reverseBetween(ListNode head, int left, int right) {
+            ListNode pre = new ListNode(-1, head);
+            ListNode index = pre;
+            for (int i = 0; i < left - 1; i++) {
+                index = index.next;
+            }
+
+            ListNode revHead = index.next;
+            ListNode indexB = pre;
+            for (int i = 0; i < right; i++) {
+                indexB = indexB.next;
+            }
+            ListNode revTail = indexB;
+            ListNode after = indexB.next;
+            // 逆转revHead到revTail
+
+            ListNode reverse = reverse(null, revHead, right - left + 1);
+            index.next = reverse;
+            revHead.next = after;
+            return pre.next;
+        }
+
+        public ListNode reverse(ListNode pre, ListNode after,int k) {
+            if (after == null) {
+                return pre;
+            }
+            if (k == 0) {
+                return pre;
+            }
+            ListNode tmp = after.next;
+            after.next = pre;
+            return reverse(after, tmp, k - 1);
+        }
+
+    }
+}