版权声明:假装有个原创声明……虽然少许博文不属于完全原创,但也是自己辛辛苦苦总结的,转载请注明出处,感谢! https://blog.csdn.net/m0_37454852/article/details/88190084
#include<algorithm>
#include<algorithm>
#include<iostream>
#include<cstdio>
#include<cstring>
#include <ctime>
#include <cmath>
#include <vector>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <deque>
using namespace std;
typedef struct BiTNode
{
int data;//存放索引号
bool isRoot;//是否为根节点标志
struct BiTNode *lChild, *rChild;
}BiTNode, *BiTree;
const int MAX = 50;
BiTree P[MAX];
bool isComplete(BiTree ROOT, BiTree &LAST)//判断是否为完全二叉树,若是则用LAST返回其最后一个节点
{//判断标准是,层次遍历,若某节点无孩子后,之后不应再有孩子;否则不是完全二叉树
queue<BiTree> Q;
BiTree T = ROOT;
Q.push(T);
int flag = 0;
while(!Q.empty())
{
T = Q.front();
LAST = T;
Q.pop();
if(T->lChild)
{
Q.push(T->lChild);
if(flag) return false;
}
else flag = 1;
if(T->rChild)
{
Q.push(T->rChild);
if(flag) return false;
}
else flag = 1;
}
return true;
}
int main()
{
int N;
scanf("%d", &N);
for(int i=0; i<N; i++)//初始化
{
P[i] = new BiTNode;
P[i]->isRoot = 1;
}
for(int i=0; i<N; i++)
{
char str1[5], str2[5];
scanf("%s %s", str1, str2);//由于索引号可能是多位的,不能用char接收
P[i]->data = i;
if(!strcmp(str1, "-")) P[i]->lChild = NULL;//空
else
{
int num = 0;
sscanf(str1, "%d", &num);//用sscanf写入num
P[i]->lChild = P[num];
P[num]->isRoot = 0;//孩子不是根节点
}
if(!strcmp(str2, "-")) P[i]->rChild = NULL;
else
{
int num = 0;
sscanf(str2, "%d", &num);
P[i]->rChild = P[num];
P[num]->isRoot = 0;
}
}
int T = 0;
while(T < N && !P[T]->isRoot) T++;
BiTree ROOT = P[T], LAST = ROOT;//找出根节点
if(isComplete(ROOT, LAST)) printf("YES %d\n", LAST->data);
else printf("NO %d\n", ROOT->data);
return 0;
}