feat: add python and java solutions to leetcode problem: No.0448

Author: yanglbme

solution/0400-0499/0448.Find All Numbers Disappeared in an Array/README.md

@@ -25,22 +25,53 @@
 
 <!-- 这里可写通用的实现逻辑 -->
 
+- 遍历输入数组的每个元素一次。
+- 把 `|nums[i]|-1` 索引位置的元素标记为负数。即 `nums[|nums[i]|-1]` \* -1。
+- 然后遍历数组，若当前数组元素 `nums[i]` 为负数，说明我们在数组中存在数字 `i+1`。否则，说明数组不存在数字 `i+1`，添加到结果列表中。
+
 <!-- tabs:start -->
 
 ### **Python3**
 
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
 ```python
-
+class Solution:
+    def findDisappearedNumbers(self, nums: List[int]) -> List[int]:
+        for num in nums:
+            index = abs(num) - 1
+            if nums[index] > 0:
+                nums[index] *= -1
+        res = []
+        for i, v in enumerate(nums):
+            if v > 0:
+                res.append(i + 1)
+        return res
 ```
 
 ### **Java**
 
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
 ```java
-
+class Solution {
+    public List<Integer> findDisappearedNumbers(int[] nums) {
+        int n = nums.length;
+        for (int i = 0; i < n; ++i) {
+            int index = Math.abs(nums[i]) - 1;
+            if (nums[index] > 0) {
+                nums[index] *= -1;
+            }
+        }
+        List<Integer> res = new ArrayList<>();
+        for (int i = 0; i < n; ++i) {
+            if (nums[i] > 0) {
+                res.add(i + 1);
+            }
+        }
+        return res;
+    }
+}
 ```
 
 ### **...**

solution/0400-0499/0448.Find All Numbers Disappeared in an Array/README_EN.md

@@ -35,13 +35,40 @@
 ### **Python3**
 
 ```python
-
+class Solution:
+    def findDisappearedNumbers(self, nums: List[int]) -> List[int]:
+        for num in nums:
+            index = abs(num) - 1
+            if nums[index] > 0:
+                nums[index] *= -1
+        res = []
+        for i, v in enumerate(nums):
+            if v > 0:
+                res.append(i + 1)
+        return res
 ```
 
 ### **Java**
 
 ```java
-
+class Solution {
+    public List<Integer> findDisappearedNumbers(int[] nums) {
+        int n = nums.length;
+        for (int i = 0; i < n; ++i) {
+            int index = Math.abs(nums[i]) - 1;
+            if (nums[index] > 0) {
+                nums[index] *= -1;
+            }
+        }
+        List<Integer> res = new ArrayList<>();
+        for (int i = 0; i < n; ++i) {
+            if (nums[i] > 0) {
+                res.add(i + 1);
+            }
+        }
+        return res;
+    }
+}
 ```
 
 ### **...**

solution/0400-0499/0448.Find All Numbers Disappeared in an Array/Solution.java

@@ -1,15 +1,18 @@
 class Solution {
     public List<Integer> findDisappearedNumbers(int[] nums) {
-        List<Integer> result = new ArrayList<>();
-        boolean[] inx = new boolean[nums.length + 1];
-        for (int num : nums) {
-            inx[num] = true;
+        int n = nums.length;
+        for (int i = 0; i < n; ++i) {
+            int index = Math.abs(nums[i]) - 1;
+            if (nums[index] > 0) {
+                nums[index] *= -1;
+            }
         }
-        for (int i = 1, length = nums.length; i <= length; i++) {
-            if (!inx[i]) {
-                result.add(i);
+        List<Integer> res = new ArrayList<>();
+        for (int i = 0; i < n; ++i) {
+            if (nums[i] > 0) {
+                res.add(i + 1);
             }
         }
-        return result;
+        return res;
     }
 }

solution/0400-0499/0448.Find All Numbers Disappeared in an Array/Solution.py

@@ -0,0 +1,11 @@
+class Solution:
+    def findDisappearedNumbers(self, nums: List[int]) -> List[int]:
+        for num in nums:
+            index = abs(num) - 1
+            if nums[index] > 0:
+                nums[index] *= -1
+        res = []
+        for i, v in enumerate(nums):
+            if v > 0:
+                res.append(i + 1)
+        return res