uva 122 Trees on the level 二叉树的层次遍历（bfs）

#include<cstring>
#include<string>
#include<cstdio>
#include<cstdlib>
#include<iostream>
#include<cmath>
#include<algorithm>
#include<queue>
#include<vector>
#include<map>
#include<stack>
#include<climits>
#include<cctype>
#include<bitset>
#include<set>
using namespace std;
#define mod 1000000007
#define PI acos(-1.0)
#define INF 0x3f3f3f3f
typedef long long LL;
char s[50];
bool failed;
struct Node{
bool have_value;
int v;
Node *left,*right;
Node():have_value(0),left(NULL),right(NULL){}
};
Node *root;
Node* newnode(){return new Node();}
void addnode(int v,char* s){
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=1;
u->v=v;
u->have_value=1;
}
bool read_input(){
failed=0;
root=newnode();
while(1){
if(scanf("%s",s)!=1)return 0;
if(!strcmp(s,"()"))break;
int v;
sscanf(s+1,"%d",&v);
addnode(v,strchr(s,',')+1);
}
return 1;
}
bool bfs(vector<int>& ans){
queue<Node*>q;
ans.clear();
q.push(root);
while(!q.empty()){
Node* u=q.front();q.pop();
if(!u->have_value)return 0;
ans.push_back(u->v);
if(u->left!=NULL)q.push(u->left);
if(u->right!=NULL)q.push(u->right);
}
return 1;
}

int main()
{
while(read_input()){
if(failed)cout<<"not complete"<<endl;
else {
vector<int>ans;
if(!bfs(ans)){
cout<<"not complete"<<endl;
}
else {
printf("%d",ans[0]);
for(int i=1;i<ans.size();i++){
printf(" %d",ans[i]);
}
cout<<endl;
}
}
}
return 0;
}