<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:
void dfs(int ch,vector<int>&dp,map<int,vector<int>>&adj,int pa,vector<int>&fa){
if(adj[ch].size()==1&& ch!=0){
    fa[ch]=adj[ch][0];
    dp[ch]=1;
    return ;
}
for(auto it:adj[ch]){
    if(it!=pa){

        dfs(it,dp,adj,ch,fa);
    }
}

for(auto it:adj[ch]){
    if(it!=pa){
       dp[ch]=dp[ch]+dp[it];
       fa[it]=ch;
    }
}
dp[ch]++;
return;

}
    vector<int> sumOfDistancesInTree(int n, vector<vector<int>>& edges) {
              vector<int>dp(n+1,0);
        map<int,vector<int>>adj;
        for(int i=0;i<edges.size();i++){
            adj[edges[i][0]].push_back(edges[i][1]);
            adj[edges[i][1]].push_back(edges[i][0]);
        }

vector<int>fa(n+1,-1);
        dfs(0,dp,adj,-1,fa);
queue<pair<int,int>>qq;
qq.push({0,0});
vector<int>vis(n+1,0);
vis[0]=1;
int ans=0;
while(qq.size()!=0){
    pair<int,int>pr=qq.front();
 qq.pop();
 ans=ans+pr.second;
 for(auto it:adj[pr.first]){
    if(vis[it]==0){
        qq.push({it,pr.second+1});
        vis[it]=1;
    }
 }
}
map<int,int>mp;
mp[0]=ans;
queue<int>qt;
qt.push(0);
vector<int>v2(n+1,0);
v2[0]=1;
while(qt.size()>0){

    int xx=qt.front();
    qt.pop();
    for(auto it:adj[xx]){
        if(v2[it]==0){
            qt.push(it);
            v2[it]=1;
        }
    }

    if(xx==0){
        continue;
    }
    int pf=fa[xx];
    int ss=mp[pf];
    mp[xx]=ss-dp[xx]+(n-dp[xx]);

}
vector<int>ab;
for(int i=0;i<n;i++){
   ab.push_back(mp[i]);
}


return ab;

    }
};
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