Improved task 3898

Author: javadev

src/main/java/g3801_3900/s3898_find_the_degree_of_each_vertex/readme.md

@@ -1 +1,61 @@
-3898\.
+3898\. Find the Degree of Each Vertex
+
+Easy
+
+You are given a 2D integer array `matrix` of size `n x n` representing the adjacency matrix of an undirected graph with `n` vertices labeled from 0 to `n - 1`.
+
+*   `matrix[i][j] = 1` indicates that there is an edge between vertices `i` and `j`.
+*   `matrix[i][j] = 0` indicates that there is no edge between vertices `i` and `j`.
+
+The **degree** of a vertex is the number of edges connected to it.
+
+Return an integer array `ans` of size `n` where `ans[i]` represents the degree of vertex `i`.
+
+**Example 1:**
+
+![](https://assets.leetcode.com/uploads/2026/03/14/g41f.png)
+
+**Input:** matrix = [[0,1,1],[1,0,1],[1,1,0]]
+
+**Output:** [2,2,2]
+
+**Explanation:**
+
+*   Vertex 0 is connected to vertices 1 and 2, so its degree is 2.
+*   Vertex 1 is connected to vertices 0 and 2, so its degree is 2.
+*   Vertex 2 is connected to vertices 0 and 1, so its degree is 2.
+
+Thus, the answer is `[2, 2, 2]`.
+
+**Example 2:**
+
+![](https://assets.leetcode.com/uploads/2026/03/14/g42f.png)
+
+**Input:** matrix = [[0,1,0],[1,0,0],[0,0,0]]
+
+**Output:** [1,1,0]
+
+**Explanation:**
+
+*   Vertex 0 is connected to vertex 1, so its degree is 1.
+*   Vertex 1 is connected to vertex 0, so its degree is 1.
+*   Vertex 2 is not connected to any vertex, so its degree is 0.
+
+Thus, the answer is `[1, 1, 0]`.
+
+**Example 3:**
+
+**Input:** matrix = [[0]]
+
+**Output:** [0]
+
+**Explanation:**
+
+There is only one vertex and it has no edges connected to it. Thus, the answer is `[0]`.
+
+**Constraints:**
+
+*   `1 <= n == matrix.length == matrix[i].length <= 100`
+*   `matrix[i][i] == 0`
+*   `matrix[i][j]` is either 0 or 1
+*   `matrix[i][j] == matrix[j][i]`