Trees on the level UVa 122

https://vjudge.net/problem/UVA-122
学习的第一个关于树的题目，按着紫书上的思路来的。再整理一下

#include<iostream>
#include<cstdio>
#include<queue>
#include<cstring>

using namespace std;

struct Node{//结点的结构体
    bool have_value;
    int v;
    Node *left,*right;
    Node():have_value(false),left(NULL),right(NULL){}
};

vector<int> ans;
void addnode(int v,char* s);
Node * root;
bool failed;
Node*newnode(){return new Node();}
const int maxn = 300;
char s[maxn];
bool read_input(){ //读取数据
    failed = false;
    root = newnode();
    for(;;)
    {
        if(scanf("%s",s) != 1)return false;//如果没有输入 跳出
        if(!strcmp(s,"()"))break;
        int v;
        sscanf(&s[1],"%d",&v);
        addnode(v,strchr(s,',')+1);//strchr ：查找字符串s中首次出现字符c的位置。
    }
    return true;
}
void addnode(int v,char* s){//建树，添加结点 并在该节点赋值
    int n = strlen(s);
    Node* u = root;
    for(int i = 0 ; i < n ; i++)
    {
        if(s[i] == 'L'){
            if(u->left == NULL) u->left = newnode();
            u = u->left;
        }else if(s[i] == 'R'){
            if(u->right == NULL) u-> right = newnode();
            u = u ->right;
        }
    }
    if(u -> have_value) failed = true;//如果有重复输入。该测试数据无效
    u->v = v;
    u->have_value = true;
}
bool bfs(){//遍历树，储存数据到ans向量中
    queue<Node*> q;
    ans.clear();
    q.push(root);
    while(!q.empty()){
        Node* u = q.front(); q.pop();
        if(!u->have_value)return false;//如果树不完整 该测试数据无效
        ans.push_back(u->v);
        if(u->left != NULL) q.push(u->left);
        if(u->right != NULL) q.push(u->right);
    }
    return true;
}
int main()
{
    while(read_input())
    {
        if(bfs()&&!failed){
            for(vector<int>::iterator it = ans.begin();it!=ans.end();it++)
            {
                if(it!=ans.begin()) cout << " " ;
                cout<<*it;
            }
            cout <<endl;
        }
        else{ cout <<"not complete"<<endl;}
    }
    return 0;
}