建立文件树，并打印

交大复试上机题
给你一串路径，譬如： a\b\c a\d\e b\cst d\ 你把这些路径中蕴含的目录结构给画出来，子目录直接列在父目录下面，并比父目录向右缩一格。
递归地建树，递归地打印。

#include <iostream>
#include <string>
#include <vector>

using namespace std;

struct node{
    
    
    string name;
    vector<node*> child;
};

void insertTree(node* &root, vector<string>& filepath, int layer, int n);
void printTree(node* &root);
void DFS(node* &root, int layer);

int main(){
    
    
    int n;
    cin>>n;
    node* root = new node;
    root->name = "root";
    while(n--){
    
    
        string path;
        cin>>path;
        vector<string> filepath;
        int s=0, e=0;
        while(e!=-1 && s<path.size()){
    
    
            e = path.find_first_of('\\', s);
            if(e!=-1) filepath.emplace_back(path.substr(s, e-s));
            else filepath.emplace_back(path.substr(s));
            s = e + 1;
        }
        insertTree(root, filepath, 0, filepath.size());
    }
    printTree(root);
    return 0;
}

void insertTree(node* &root, vector<string>& filepath, int layer, int n){
    
    
    if(layer>=n) return;
    bool exist = false;
    int i, child_num = root->child.size();
    for(i=0; i<child_num; i++){
    
    
        if(root->child[i]->name == filepath[layer]){
    
    
            exist = true;
            break;
        }
        else if(root->child[i]->name > filepath[layer]) break;
    }
    if(!exist){
    
    
        node* temp = new node;
        temp->name = filepath[layer];
        root->child.emplace(root->child.begin()+i, temp);
    }
    insertTree(root->child[i], filepath, layer+1, n);
    return;
}

void printTree(node* &root){
    
    
    int n = root->child.size();
    for(int i=0; i<n; i++) DFS(root->child[i], 0);
    return;
}

void DFS(node* &root, int layer){
    
    
    for(int i=0; i<layer; i++) cout<<' ';
    cout<<root->name<<endl;
    int n = root->child.size();
    for(int i=0; i<n; i++) DFS(root->child[i], layer+1);
    return;
}