7-6 Is a complete binary search tree (30 points)

To insert a sequence of given numbers into an initially empty binary search tree (defined as the left subtree with a large key and a right subtree with a small key), you need to determine whether the final tree is a complete binary tree, and give The result of its level-order traversal.

Input format:

The first line of input gives a positive integer up to 20 N; the second line gives Ndifferent positive integers separated by spaces.

Output format:

Insert the input Npositive integers sequentially into an initially empty binary search tree. In the first line, output the result of the hierarchical traversal of the result tree. The numbers are separated by 1 space, and there must be no extra spaces at the beginning and end of the line. The second line of output YES, if the tree is a complete binary tree; otherwise output NO.

Input sample 1:

9
38 45 42 24 58 30 67 12 51

Sample output 1:

38 45 24 58 42 30 12 67 51
YES

Input sample 2:

8
38 24 12 45 58 67 42 51

Sample output 2:

38 45 24 58 42 12 67 51
NO

 

 

 

 

code

 

 

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int a[100],b;
int n;
void add(int i,int d)
{
if(a[i] == -1)
{
a[i] = d;
return;
}
if(d > a[i])add(i*2,d);
else add(i*2+1,d);
}
int main()
{
scanf("%d",&n);
memset(a,-1,sizeof(a));
for(int i = 0;i < n;i ++)
{
scanf("%d",&b);
add(1,b);
}
int c = 0,i = 0;
while(c < n)
{
while(a[i] == -1)i++;
if(c)printf(" %d",a[i]);
else printf("%d",a[i]);
i ++;
c ++;
}
if(i == n + 1)printf("\nYES");
else printf("\nNO");
}