N-叉树--给定顶点求N叉树的最大深度

#include<iostream>
#include<vector>
using namespace std;

vector<int> Vec[100005];

int Result;

void dfs(int Child,int Parent,int PathLength){
    for(int i =0 ;i < Vec[Child].size();i ++){
        if(Vec[Child][i] == Parent){
            continue;
        }
        dfs(Vec[Child][i],Child,PathLength +1);
    }
    Result = max(Result,PathLength);
}

int main(){
    int n;
    scanf("%d",&n);
    for(int i = 0;i < n;i ++){
        int x,y;
        scanf("%d%d",&x,&y);
        Vec[x].push_back(y);
        Vec[y].push_back(x);
    }
    Result = 0;
    dfs(1,-1,0);
    printf("%d\n",(n - 1) * 2 - Result);
    return 0;
}