Is Graph Bipartite — BFS 2-Coloring

from collections import deque
class Solution:
    def isBipartite(self, graph: list[list[int]]) -> bool:
        n=len(graph); color=[-1]*n
        for i in range(n):
            if color[i]!=-1: continue
            q=deque([i]); color[i]=0
            while q:
                u=q.popleft()
                for v in graph[u]:
                    if color[v]==-1: color[v]=1-color[u]; q.append(v)
                    elif color[v]==color[u]: return False
        return True

class Solution {
public:
    bool isBipartite(vector<vector<int>>& g){
        int n=g.size(); vector<int> col(n,-1);
        for(int i=0;i<n;i++){
            if(col[i]!=-1) continue;
            queue<int> q; q.push(i); col[i]=0;
            while(!q.empty()){
                int u=q.front();q.pop();
                for(int v:g[u]){
                    if(col[v]==-1){col[v]=1-col[u];q.push(v);}
                    else if(col[v]==col[u]) return false;
                }
            }
        }
        return true;
    }
};