1102. Invert a Binary Tree (25)
时间限制 400 ms 内存限制 65536 kB 代码长度限制 16000 B
判题程序 Standard 作者 CHEN, Yue
The following is from Max Howell @twitter:
Google: 90% of our engineers use the software you wrote (Homebrew), but you can’t invert a binary tree on a whiteboard so fuck off.
Now it’s your turn to prove that YOU CAN invert a binary tree!
Input Specification:
Each input file contains one test case. For each case, the first line gives a positive integer N (<=10) which is the total number of nodes in the tree – and hence the nodes are numbered from 0 to N-1. Then N lines follow, each corresponds to a node from 0 to N-1, and gives the indices of the left and right children of the node. If the child does not exist, a “-” will be put at the position. Any pair of children are separated by a space.
Output Specification:
For each test case, print in the first line the level-order, and then in the second line the in-order traversal sequences of the inverted tree. There must be exactly one space between any adjacent numbers, and no extra space at the end of the line.
Sample Input:
8
1 -
- -
0 -
2 7
- -
- -
5 -
4 6
Sample Output:
3 7 2 6 4 0 5 1
6 5 7 4 3 2 0 1
#define _CRT_SECURE_NO_WARNINGS
#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <sstream>
#include <memory.h>
using namespace std;
const int MaxN = 12;
int Num[MaxN],N,P = 0,L = 0;
bool isRoot[MaxN];
typedef struct tnode
{
int data;
struct tnode * lchild;
struct tnode * rchild;
}TNode;
TNode *Ptr[MaxN];
void Level(TNode * root)
{
if (!root) return;
queue<TNode *>que; que.push(root);
while (que.size())
{
TNode * node = que.front(); que.pop();
++L;
cout << node->data;
if (L != N)
cout << " ";
if (node->rchild) que.push(node->rchild);
if (node->lchild) que.push(node->lchild);
}
}
void InOrder(TNode * root)
{
if (!root)return;
InOrder(root->rchild);
cout << root->data; ++P;
if (P != N)
cout << " ";
InOrder(root->lchild);
delete root;
}
TNode * CreateTree(int N)
{
for (int i = 0; i < N; ++i)
{
Ptr[i] = new TNode;
Ptr[i]->data = i;
Ptr[i]->lchild = Ptr[i]->rchild = NULL;
}
stringstream ss; string str;
for (int i = 0; i < N; ++i)
{
getline(cin, str);
ss << str;
int k = 0;
if (str[k] == '-')
{
Ptr[i]->lchild = NULL;
ss.get();
ss.get();
}
else
{
int lidx;
ss >> lidx;
Ptr[i]->lchild = Ptr[lidx];
isRoot[lidx] = false;
}
while (str[k] != ' ')
++k;
if (str[k+1] == '-')
{
Ptr[i]->rchild = NULL;
}
else
{
int ridx;
ss >> ridx;
Ptr[i]->rchild = Ptr[ridx];
isRoot[ridx] = false;
}
ss.clear();
ss.str("");
}
TNode * root = NULL;
for (int i = 0; i < N; ++i)
{
if (isRoot[i])
{
root = Ptr[i];
break;
}
}
return root;
}
int main()
{
#ifdef _DEBUG
freopen("data.txt", "r+", stdin);
#endif
std::ios::sync_with_stdio(false);
memset(isRoot, 1, sizeof(isRoot));
cin >> N; cin.get();
TNode * root = CreateTree(N);
Level(root); cout << endl;
InOrder(root);
return 0;
}