PAT甲题题解-1064. Complete Binary Search Tree (30)-中序和层次遍历，水

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <string.h>
#include <queue>
using namespace std;
const int maxn=1005;
int a[maxn];
int node[maxn];
int cnt=0;
void build(int root,int n){
    if(cnt>n)
        return;
    if(root>n)
        return;
    build(root<<1,n);
    node[root]=a[++cnt];
//printf("id:%d val:%d\n",root,node[root]);
    build((root<<1)|1,n);
}
void BFS(int root,int n){
    queue<int> q;
    q.push(root);
    int v;
    bool first=true;
    while(!q.empty()){
        v=q.front();
        q.pop();
        if(first){
            first=false;
            printf("%d",node[v]);
        }
        else
            printf(" %d",node[v]);
        if(v*2<=n)
            q.push(v*2);
        if(v*2+1<=n)
            q.push(v*2+1);
    }

}
int main()
{
    int n;
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
        scanf("%d",&a[i]);
    sort(a+1,a+n+1);
    build(1,n);
    BFS(1,n);

    return 0;
}