<p>There is an undirected connected tree with <code>n</code> nodes labeled from <code>0</code> to <code>n - 1</code> and <code>n - 1</code> edges.</p>

<p>You are given the integer <code>n</code> and the array <code>edges</code> where <code>edges[i] = [a<sub>i</sub>, b<sub>i</sub>]</code> indicates that there is an edge between nodes <code>a<sub>i</sub></code> and <code>b<sub>i</sub></code> in the tree.</p>

<p>Return an array <code>answer</code> of length <code>n</code> where <code>answer[i]</code> is the sum of the distances between the <code>i<sup>th</sup></code> node in the tree and all other nodes.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/07/23/lc-sumdist1.jpg" style="width: 304px; height: 224px;" />
<pre>
<strong>Input:</strong> n = 6, edges = [[0,1],[0,2],[2,3],[2,4],[2,5]]
<strong>Output:</strong> [8,12,6,10,10,10]
<strong>Explanation:</strong> The tree is shown above.
We can see that dist(0,1) + dist(0,2) + dist(0,3) + dist(0,4) + dist(0,5)
equals 1 + 1 + 2 + 2 + 2 = 8.
Hence, answer[0] = 8, and so on.
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/07/23/lc-sumdist2.jpg" style="width: 64px; height: 65px;" />
<pre>
<strong>Input:</strong> n = 1, edges = []
<strong>Output:</strong> [0]
</pre>

<p><strong class="example">Example 3:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/07/23/lc-sumdist3.jpg" style="width: 144px; height: 145px;" />
<pre>
<strong>Input:</strong> n = 2, edges = [[1,0]]
<strong>Output:</strong> [1,1]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= n &lt;= 3 * 10<sup>4</sup></code></li>
	<li><code>edges.length == n - 1</code></li>
	<li><code>edges[i].length == 2</code></li>
	<li><code>0 &lt;= a<sub>i</sub>, b<sub>i</sub> &lt; n</code></li>
	<li><code>a<sub>i</sub> != b<sub>i</sub></code></li>
	<li>The given input represents a valid tree.</li>
</ul>

class Solution {
public: 
    int dfs(int node,vector<int> adj[],vector<int> &up,vector<int> &down,vector<int> &vis,int n)
    {
        vis[node]=1;
        int ans=0;
        for(auto it:adj[node])
        {
            if(!vis[it])
            {
                ans+=dfs(it,adj,up,down,vis,n);
            }
        }
        down[node]=ans+1;
        up[node]=n-down[node];
        return ans+1;

    }
    int solve(int node,vector<int> adj[],int n)
    {
        int ans=0;
        vector<int> vis(n);
        queue<pair<int,int>> q;
        q.push({0,node});
        vis[node]=1;
        while(!q.empty())
        {
            auto it=q.front();
            q.pop();
            int d=it.first;
            int k=it.second;
            ans+=d;
            for(auto it:adj[k])
            {
                if(!vis[it])
                {
                    vis[it]=1;
                    q.push({d+1,it});
                }
            }
        }
        return ans;
    }
    void dfs2(int node,vector<int> &ans,vector<int> adj[],vector<int> &up,vector<int> &down,vector<int> &vis)
    {
        vis[node]=1;
        for(auto it:adj[node])
        {
            if(!vis[it])
            {
                ans[it]=ans[node]-down[it]+up[it];
                dfs2(it,ans,adj,up,down,vis);
            }
        }
    }
    vector<int> sumOfDistancesInTree(int n, vector<vector<int>>& edges) {
        vector<int> ans(n);
        vector<int> adj[n];
        for(int i=0;i<edges.size();i++)
        {
            int u=edges[i][0];
            int v=edges[i][1];
            adj[u].push_back(v);
            adj[v].push_back(u);

        }
        int t=solve(0,adj,n);
        ans[0]=t;
        vector<int> up(n);
        vector<int> down(n);
        vector<int> vis(n);
        dfs(0,adj,up,down,vis,n);
        for(int i=0;i<n;i++)
        {
            cout<<up[i]<<" "<<down[i]<<endl;
        }
        for(int i=0;i<n;i++)
        vis[i]=0;

        dfs2(0,ans,adj,up,down,vis);

        return ans;

    }
};
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