Leetcode-5056 Flower Planting With No Adjacent(不邻接植花)

#define _for(i,a,b) for(int i = (a);i < b;i ++)

int n,m;

class Solution
{
    public:
        int color[10000];
        vector<vector<int>> a;
        bool OK(int t)
        {
            for(int j=0; j<a[t].size(); j++)
            {
            //    if(a[t][j])
            //    {
                if(color[t]==color[a[t][j]])
                        return false;
            //    }
            }
            return true;
        }
        bool traceback(int t)
        {
            int oldvalue=0;
            if(t==n)
            {
                return true;
            }
            for(int i=1; i<=m; i++) 
            {
                oldvalue=color[t];
                color[t]=i;
                if(OK(t))
                {
                    if(traceback(t+1)) return true;
                }
                color[t]=oldvalue;
            }
            return false;
        }
        vector<int> gardenNoAdj(int N, vector<vector<int>>& paths)
        {
            a.resize(10000);
            n = N;
            m = 4;
            _for(i,0,paths.size())
            {a[paths[i][0]-1].push_back(paths[i][1]-1);a[paths[i][1]-1].push_back(paths[i][0]-1);}
            
            traceback(0);
            vector<int> rnt(N,0);
            _for(i,0,N)
                rnt[i] = color[i];
            return rnt;
        }
};

染色问题，没想太多，搜就完事了