Decide Whether an Undirected Graph Can Be Two-Colored

### Problem graph is an undirected adjacency list that may be disconnected. Decide whether its vertices can be split into two sets so that every edge joins different sets. There are no self-loops or repeated neighbors. ```cpp class Solution { public: bool isBipartite(vector<vector<int>>& graph); }; ``` ### Examples **Example 1:** ```text graph = [[1],[0],[]] Output: true Explanation: Put vertices0 and2 on one side and vertex1 on the other. ``` **Example 2:** ```text graph = [[1,2],[0,2],[0,1]] Output: false Explanation: A triangle cannot be colored using two colors with different ends on every edge. ``` ### Constraints - Vertex count V lies in [1,100], with labels 0 through V-1. - Each neighbor list contains fewer than V distinct valid labels and excludes its own vertex. - Every adjacency appears in both directions. ### Contract considerations Preserve symmetric undirected adjacency and allow disconnected graphs. ```hint Read the boundary condition What color must a neighbor of a colored vertex have? ``` ### Boundary reminders Preserve symmetric undirected adjacency and allow disconnected graphs.