Odd cycle detect in a graph

//sudo code
// vertex are colored with black & white colors
//http://codeforces.com/contest/557/submission/11870749
for(int i=0;i<n;i++)
    {
        if(!vis[i])
            dfs(i,0);
        for(auto u:v[i])
            if(color[u]==color[i]){
                return "found odd cycle";
            }
    }