二叉樹的建立與四種遍歷方式
阿新 • • 發佈:2019-02-18
#include <bits/stdc++.h>
using namespace std;
typedef struct node {
char data;
struct node *lchild;
struct node *rchild;
} Node, *Bitree;
char ch;
Bitree T;
Node *CreateBitree() {
cin >> ch;
Bitree T;
if(ch == '#') T = NULL;//注意:二叉樹的輸入需要嚴格遵守以#結尾的規則,並且輸入順序按照前序遍歷的方式
else {
T = new node;
T->data = ch;
T->lchild = CreateBitree();
T->rchild = CreateBitree();
}
return T;
}
void PreOrder(Bitree T) {//前序遍歷
if(T) {
cout << T->data << " ";
PreOrder(T->lchild);
PreOrder(T->rchild);
}
}
void InOrder(Bitree T) {//中序遍歷
if(T) {
InOrder(T->lchild);
cout << T->data << " ";
InOrder(T->rchild);
}
}
void PostOrder(Bitree T) {//後序遍歷
if(T) {
PostOrder(T->lchild);
PostOrder(T->rchild);
cout << T->data << " ";
}
}
void bfs(vector<char>& ans, Bitree T) {//層序遍歷
queue<Bitree>q;
ans.clear();
q.push(T);
while(!q.empty()) {
Bitree u = q.front();
q.pop();
if(u->data != 0)ans.push_back(u->data);
if(u->lchild != NULL) q.push(u->lchild);
if(u->rchild != NULL) q.push(u->rchild);
}
}
void Remove(Bitree T) {//回收記憶體
if(T == NULL) return;
Remove(T->lchild);
Remove(T->rchild);
delete T;
}
int main() {
Bitree T;
T = CreateBitree();
cout << "前序遍歷為 ";
PreOrder(T);
cout << endl << "中序遍歷為 ";
InOrder(T);
cout << endl << "後序遍歷為 ";
PostOrder(T);
cout << endl << "層序遍歷為 ";
vector<char>v;
vector<char>::iterator it;
bfs(v, T);
for(it = v.begin(); it != v.end(); it++) cout << *it << " ";
Remove(T);
return 0;
}
using namespace std;
typedef struct node {
char data;
struct node *lchild;
struct node *rchild;
} Node, *Bitree;
char ch;
Bitree T;
Node *CreateBitree() {
cin >> ch;
Bitree T;
if(ch == '#') T = NULL;//注意:二叉樹的輸入需要嚴格遵守以#結尾的規則,並且輸入順序按照前序遍歷的方式
else {
T = new node;
T->data = ch;
T->lchild = CreateBitree();
T->rchild = CreateBitree();
}
return T;
}
void PreOrder(Bitree T) {//前序遍歷
if(T) {
cout << T->data << " ";
PreOrder(T->lchild);
PreOrder(T->rchild);
}
}
void InOrder(Bitree T) {//中序遍歷
if(T) {
InOrder(T->lchild);
cout << T->data << " ";
InOrder(T->rchild);
}
}
void PostOrder(Bitree T) {//後序遍歷
if(T) {
PostOrder(T->lchild);
PostOrder(T->rchild);
cout << T->data << " ";
}
}
void bfs(vector<char>& ans, Bitree T) {//層序遍歷
queue<Bitree>q;
ans.clear();
q.push(T);
while(!q.empty()) {
Bitree u = q.front();
q.pop();
if(u->data != 0)ans.push_back(u->data);
if(u->lchild != NULL) q.push(u->lchild);
if(u->rchild != NULL) q.push(u->rchild);
}
}
void Remove(Bitree T) {//回收記憶體
if(T == NULL) return;
Remove(T->lchild);
Remove(T->rchild);
delete T;
}
int main() {
Bitree T;
T = CreateBitree();
cout << "前序遍歷為 ";
PreOrder(T);
cout << endl << "中序遍歷為 ";
InOrder(T);
cout << endl << "後序遍歷為 ";
PostOrder(T);
cout << endl << "層序遍歷為 ";
vector<char>v;
vector<char>::iterator it;
bfs(v, T);
for(it = v.begin(); it != v.end(); it++) cout << *it << " ";
Remove(T);
return 0;
}