PAT1099

/*innner order traverse for BST will be ordered
*1.sort the value in buffer
*2.inner traverse the BST and insert the value
*3.be careful for the formatted output
*4.level traverse output using queue
*/

/*c-style code
* abusing in global variable
*not good encapsulation
*may be possible to use reference for 'start'
*/

 #include <cstdio>
 #include<algorithm>
 #include<cstring>
 #include<queue>
 #define maxn 100
 using  namespace std;
 typedef struct {
     int left,right;
     int value;
     int inserted;
 }binode;
 binode bitree[maxn];
 int buf[maxn];
 int start=;
 queue<int> q;
 void middle_insert(int root)
 {
     if(root==-)return;
     middle_insert(bitree[root].left);
     if(bitree[root].left==- || bitree[bitree[root].left].inserted==)
     {
         bitree[root].value=buf[start];
         bitree[root].inserted=;
         start++;
         //return ;
     }
     middle_insert(bitree[root].right);
 }
 void level_traverse()
 {
     int i=;
     q.push();
     while(!q.empty())
     {
         int tmp=q.front();
         buf[i++]=bitree[tmp].value;
         q.pop();
         if(bitree[tmp].left!=-)q.push(bitree[tmp].left);
         if(bitree[tmp].right!=-)q.push(bitree[tmp].right);
     }
 }
 int main()
 {
     //freopen("input.txt","r",stdin);
     int i,n;
     while(cin>>n)
     {
         memset(buf,,sizeof(buf));
         memset(bitree,,sizeof(bitree));
         //fill(bitree,bitree+n,0); parameter must be iterator
         for(i=;i<n;i++)scanf(" %d %d",&bitree[i].left,&bitree[i].right);
         for(i=;i<n;i++)scanf(" %d",&buf[i]);
         sort(buf,buf+n);
         //for(i=0;i<n;i++)printf("%d ",buf[i]);
         middle_insert();
         //for(i=0;i<n;i++)printf("%d %d %d %d\n",i,bitree[i].left,bitree[i].right,bitree[i].value);
         level_traverse();
         for(i=;i<n;i++){
             if(i<n-)printf("%d ",buf[i]);
             else printf("%d\n",buf[i]);
         }
     }
     return ;
 }

IMPROVE IN  C++

 #include <cstdio>
 #include <iostream>
 #include<algorithm>
 #include<cstring>
 #include<queue>
 #define maxn 100
 using  namespace std;
 typedef struct {
     int left,right;
     int value;
     int inserted;
 }binode;

 binode bitree[maxn];
 int buf[maxn];
 void middle_insert(int root,int &start)
 {
     if(root==-)return;
     middle_insert(bitree[root].left,start);
     if(bitree[root].left==- || bitree[bitree[root].left].inserted==)
     {
         bitree[root].value=buf[start];
         bitree[root].inserted=;
         start++;
         //return ;
     }
     middle_insert(bitree[root].right,start);
 }
 void level_traverse(binode bitree[],int buf[])
 {
     queue<int> q;
     int i=;
     q.push();
     while(!q.empty())
     {
         int tmp=q.front();
         buf[i++]=bitree[tmp].value;
         q.pop();
         if(bitree[tmp].left!=-)q.push(bitree[tmp].left);
         if(bitree[tmp].right!=-)q.push(bitree[tmp].right);
     }
 }
 int main()
 {

     freopen("input.txt","r",stdin);
     int n;
     while(cin>>n)
     {
         memset(buf,,sizeof(buf));
         memset(bitree,,sizeof(bitree));
         for(int i=;i<n;i++)cin>>bitree[i].left>>bitree[i].right;
         for(int i=;i<n;i++)cin>>buf[i];
         sort(buf,buf+n);
         //for(i=0;i<n;i++)printf("%d ",buf[i]);
         int start=;
         middle_insert(,start);
         //for(i=0;i<n;i++)printf("%d %d %d %d\n",i,bitree[i].left,bitree[i].right,bitree[i].value);
         level_traverse(bitree,buf);
         for(int i=;i<n;i++){
             cout<<buf[i];
             i==n-?cout<<endl:cout<<' ';
         }
     }
     return ;
 }