树的层次遍历_level

UVA 122

照着书写得一脸懵逼也是醉了。。。意识到掌握语言的技巧的重要性，sscanf大法好，new大法好。
还有为什么加了remove就不对了。。。爆内存之类的，刘汝佳老师求解释

#include
#include
#include
#include
using namespace std;

bool failed;
//节点类型
struct Node{
    bool have_value;                                  //是否被赋值过
    int v;                                            //节点值
    Node *left, *right;
    Node():have_value(false),left(NULL),right(NULL){} //构造函数
};

Node* root;                                           //二叉树的根节点
Node* newnode() { return new Node(); }

void remove_tree(Node* u) {
    if(u == NULL) return;
    remove_tree(u->left);
    remove_tree(u->right);
    delete u;
}

void addnode(int v, char* s){
    int n = strlen(s);
    //remove_tree(root);
    Node* u = root;                                    //从根节点往下走
    for(int i = 0; i < n; i++)
        if(s[i] == 'L'){
            if(u->left == NULL) u->left = newnode();   //节点不存在，建立新节点
            u = u->left;                               //往左走
        }
        else if(s[i] == 'R'){
            if(u->right == NULL) u->right = newnode();
            u = u->right;
        }                                              //忽略其他情况，即最后多余的那个右括号
    if(u->have_value) failed = true;                   //已经赋过值，表明输入有误
    u->v = v;
    u->have_value = true;                              //做标记
}

char s[1000];                                  //保存读入节点
bool read_input(){
    failed = false;
    root = newnode();                         //创建根节点
    for(;;){
        if(scanf("%s", s) != 1) return false; //整个输入结束
        if(!strcmp(s, "()")) break;           //结束标志，退出循环
        int v;
        sscanf(&s[1], "%d", &v);              //读入节点值
        addnode(v, strchr(s, ',')+1);         //查找逗号然后插入节点
    }
    return true;
}

bool bfs(vector<int>& ans){
    queue q;
    ans.clear();
    q.push(root);
    while(!q.empty()){
        Node* u = q.front();
        q.pop();
        if(!u->have_value) return false;
        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(){
    freopen("level.in", "r", stdin);
    freopen("level.out", "w", stdout);
    vector<int> ans;
    while(read_input()){
        if(failed||!bfs(ans)){
            printf("not complete\n");
        }
        else{
            int t = ans.size();
            for(int i = 0; i < t; i++){
                if(i) printf(" ");
                printf("%d",ans[i]);
            }
            printf("\n");
        }
    }
    return 0;
}