這是前一個線程,我在這個實驗室得到了幫助。我的堆棧行爲異常,至少可以說,當我添加一個項目到堆棧,稍後打印出來時,它看起來似乎沒有添加正確。如果我輸入另一個操作數(*,/,+),我總是打印出加號(+)。C++堆棧實現(不能正常工作)
我正在使用堆棧將用戶輸入,中綴表達式轉換爲後綴。它似乎工作正常,除了打印結束時在堆棧中的操作數。
#include <iostream>;
#include <vector>
using namespace std;
class DishWell{
public:
char ReturnFront(){
return Well.front();
}
void Push(char x){
Well.push_back(x);
}
void Pop(){
Well.pop_back();
}
bool IsEmpty(){
return Well.empty();
}
private:
vector<char> Well;
};
bool Precidence(char Input, char Stack){
int InputPrecidence,StackPrecidence;
switch (Input){
case '*':
InputPrecidence = 4;
break;
case '/':
InputPrecidence = 4;
break;
case '+':
InputPrecidence = 3;
break;
case '-':
InputPrecidence = 3;
break;
case '(':
InputPrecidence = 2;
break;
default:
InputPrecidence = 0;
}
switch (Stack){
case '*':
StackPrecidence = 4;
break;
case '/':
StackPrecidence = 4;
break;
case '+':
StackPrecidence = 3;
break;
case '-':
StackPrecidence = 3;
break;
case '(':
StackPrecidence = 2;
break;
default:
StackPrecidence = 0;
}
if(InputPrecidence>StackPrecidence) return true;
else return false;
}
int main(int argc, char** argv) {
DishWell DishTray;
char Input;
bool InputFlag;
InputFlag = true;
cout<<"Enter Input, invalid input will terminate"<<endl;
while(InputFlag){
cout<<"Input: ";
cin>>Input;
cout<<endl;
if((((Input>='a'&&Input<='z')||(Input>='A'&&Input<='Z'))||Input>='0'&&Input<='9')))//If Digit or Number
cout<<Input;
if((Input=='*'||Input=='/'||Input=='+'||Input=='-')){//if operand
if(DishTray.IsEmpty())
DishTray.Push(Input);
else if(Precidence(Input,DishTray.ReturnFront()))
DishTray.Push(Input);
else if(!Precidence(Input,DishTray.ReturnFront()))
cout<<"Output: "<<Input<<endl;
}
else if(!((((Input>='a'&&Input<='z')||(Input>='A'&&Input<='Z'))||(Input>='0'&&Input<='9')))||((Input=='*'||Input=='/'||Input=='+'||Input=='-')))//if not digit/numer or operand
InputFlag = false;
}
int counter = 0;
while(!DishTray.IsEmpty()){
counter++;
cout<<counter<<" Element "<<DishTray.ReturnFront()<<endl;
DishTray.Pop();
}
return 0;
謝謝MACAIRE貝爾
啊我明白了,我其實已經回到了前一篇文章。認爲我的邏輯錯了,我回來/前/第一/最後困惑。我應該改變我所有的前臺功能,使其恢復正確嗎? – Malaken 2011-01-23 02:23:42