trie树（字典树）实现 C++

#include <iostream>#include <vector>#include <string>#include <map>using namespace std;struct TrieNode{    vector<TrieNode*> next;    bool end;    int cnt;    TrieNode():end(0),cnt(0){}};TrieNode *root=new TrieNode();map<string,unsigned int> table;void build(string &str){    TrieNode *p=root;    for(unsigned int x:str)    {        if(x+1>p->next.size()) p->next.resize(x+1);        if(p->next[x]==NULL)        {            TrieNode* s=new TrieNode();            p->next[x]=s;        }        p=p->next[x];    }    p->end=true;    p->cnt++;}void searchAllword(TrieNode *p,string word){    if(p->end==true) table[word]=p->cnt;    for(unsigned int i=0;i<p->next.size();++i)    {        TrieNode *xp=p->next[i];        if(xp)            searchAllword(xp,word+(char)i);    }}int search(string &str){    TrieNode *p=root;    for(unsigned int x:str)    {        if(x>=p->next.size()||p->next[x]==NULL)            return 0;        else p=p->next[x];    }    return p->cnt;}void disp(){    for(auto x:table)        cout<<x.first<<" "<<x.second<<endl;}int main(int argc, char const *argv[]){    int n;    string str;    cout<<"input word number that you want to creat: ";    cin>>n;    while(n--)    {        cin>>str;        build(str);    }    cout<<"input word number that you want to search: ";    cin>>n;    while(n--)    {        cin>>str;        cout<<str<<" : "<<search(str)<<endl;    }    searchAllword(root,string());    cout<<"all word record\n";    disp();    return 0;}