1.前期实验
失败原因：
（1）对于先序输入的式子理解不到位，导致在压栈错误
（2）&的用法？？？？
#include <iostream>
#include <stack>
using namespace std;
void d(stack<int>&m)
{
cout<<"fuck";
cout<<m.top();
m.pop();
}
int main ()
{
stack<int> mystack;
int sum (0);
for (int i=1;i<=3;i++) mystack.push(i);
d(mystack);
cout<<"hh";
cout<<mystack.top();
return 0;
}
void Vaculcate(Tree T,stack<char>&smybol,stack<float>&number)
{
if(!T)
return;
Vaculcate(T->lchild,smybol,number);
Vaculcate(T->rchild,smybol,number);
TreeNode *p=T;
if(p->data>='0'&&p->data<='9')
{
float m=(float)(p->data-'0');
number.push(m);
cout<<"number"<<number.top()<<endl;
}
else
{
smybol.push(p->data);
cout<<"char"<<smybol.top()<<endl;
}
}
void Value(Tree T,stack<char>&smybol,stack<float>&number)
{
Vaculcate(T,smybol,number);
stack<float>answer;
while(!number.empty()) {
cout<<"no empty";
float m, n;
m = number.top();
cout<<"m:"<<m<<endl;
number.pop();
n = number.top();
cout<<"n:"<<n<<endl;
number.pop();
char x = smybol.top();
cout<<"symbol:"<<x<<endl;
smybol.pop();
float term;
switch (x) {
case '+':
term = m + n;
cout << "answer:"<<term << endl;
answer.push(term);
break;
case '-':
term = n-m;
cout << "answer:"<<term << endl;
answer.push(term);
break;
case '*':
term = m * n;
cout <<"answer:"<< term << endl;
answer.push(term);
break;
case '/':
term = n/m;
cout << "answer:"<<term << endl;
answer.push(term);
break;
default:
cout << "error";
}
}
}
3.计算表达式的值
#include <stdio.h>
#include <stack>
#include <iostream>
using namespace std;
stack<float>number;
stack<char>symbol;
int main() {
char x[20];
cin>>x;
int i=0;
int count=0;
while(x[i-1]!='#') {
if(count < 2) {
if (x[i] >= '0' && x[i] <= '9') {
count++;
float m = (float) (x[i] - '0');
number.push(m);
cout << "number:" << m << endl;
} else {
symbol.push(x[i]);
cout << "symbol:" << x[i] << endl;
}
i++;
}
else {
count = 0;
float term, a, b;
a = number.top();
number.pop();
b = number.top();
number.pop();
char p;
p = symbol.top();
symbol.pop();
cout << a << " " << b << " " << p << endl;
switch (p) {
case '+':
term = a + b;
number.push(term);
cout << term << endl;
break;
case '-':
term = b -a;
number.push(term);
cout << term << endl;
break;
case '*':
term = a * b;
number.push(term);
cout << term << endl;
break;
case '/':
term = a / b;
number.push(term);
cout << term << endl;
break;
default:
break;
}
}
}
cout<<endl;
cout<<"最终运算："<<endl;
symbol.pop();
char d = symbol.top();
float a, b;
a = number.top();
b = number.top();
cout<<a<<" "<<b<<endl;
float term;
switch (d) {
case '+':
term = a + b;
number.push(term);
cout <<"answer:"<< term << endl;
break;
case '-':
term = a - b;
number.push(term);
cout << "answer:"<<term << endl;
break;
case '*':
term = a * b;
number.push(term);
cout <<"answer:"<< term << endl;
break;
case '/':
term = a / b;
number.push(term);
cout <<"answer:"<< term << endl;
break;
default:
break;
}
return 0;
}
4.中序添加括号输出
（1）函数头文件以及自定义函数定义以及实现
//
// Created by fattytian on 17-11-22.
//
#ifndef UNTITLED11_TREE_H
#define UNTITLED11_TREE_H
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <iostream>
#include <stack>
#include <math.h>
#define MAX 100
using namespace std;
typedef char TElmeType;
typedef struct TreeNode
{
TElmeType data;//数据存储
struct TreeNode *lchild,*rchild,*parent;//左右孩子，父节点
}TreeNode,*Tree;
//创建
void Inittree(Tree *T)
{
*T=NULL;
}
//销毁
void Detree(Tree *T)
{
if(*T) {
if((*T)->lchild)
Detree(&(*T)->lchild);
if((*T)->rchild)
Detree(&(*T)->rchild);
free(*T);
*T=NULL;
}
}
//创建一个表达式的树
void Build(Tree &T,TElmeType x) {
TreeNode *newnode = new TreeNode;
newnode->data = x;
newnode->rchild = NULL;
newnode->lchild = NULL;
TreeNode *p;
if (T == NULL) {
T = newnode;
newnode->parent = T;
p = newnode;
} else {
if (x >= '0' && x <= '9') {
if (p->lchild == NULL) {
p->lchild = newnode;
newnode->parent = p;
} else {
p->rchild = newnode;
newnode->parent = p;
p = p->parent;
}
} else {
if (p->lchild != NULL) {
p->rchild = newnode;
newnode->parent = p;
p = newnode;
} else {
p->lchild = newnode;
newnode->parent = p;
p = newnode;
}
}
}
}
//前缀输出
void Expression(Tree T)
{
// cout<<"中序输出：";
if(!T)
return;
Expression(T->lchild);
cout<<T->data;
Expression(T->rchild);
}
//表达式
void Priexpression(Tree T)
{
if(!T)
return;
else {
TreeNode *p;
p = T;
cout << "完整表达式："<<endl;
while (p->lchild) {
p = p->lchild;
}
while (p != T) {
cout << "(";
cout << p->data;
p = p->parent;
cout << p->data;
cout << p->rchild->data;
cout << ")";
p = p->parent;
}
cout << p->data;
p = p->rchild;
while (p->lchild)
p = p->lchild;
while (p != T) {
cout << "(";
cout << p->data;
p = p->parent;
cout << p->data;
cout << p->rchild->data;
cout << ")";
p = p->parent;
}
}
}
#endif //UNTITLED11_TREE_H
（2）main 函数
//
// Created by fattytian on 17-11-28.
//
#include "Tree.h"
stack<char>symbol;
stack<float>number;
int main()
{
cout<<"please write your expression:";
Tree tree;
Inittree(&tree);
TElmeType x[20];
cin>>x;
int i=0;
int count=0;
while(x[i]!='#')
{
Build(tree,x[i]);
i++;
}
cout<<"表达式："<<endl;
Expression(tree);
cout<<"\n";
Priexpression(tree);
return 0;
}
5.晚安，我会想到好的方法简化代码的。
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