c 语言计算器带括号优先级,C++结合QT实现带有优先级的计算器功能

代码

MyCalculator.h

#pragma once

#include

#include

#include

#include "ui_MyCalculator.h"

class MyCalculator : public QMainWindow

{

Q_OBJECT

public:

MyCalculator(QWidget *parent = Q_NULLPTR);

/*void setnum1(int num);

void setnum2(int num);

void setflag(int f);

int calculartor();

*/

private slots:

void on_number_Button_clicked();

void on_action_Button_clicked();

void on_comma_Button_clicked();

void on_action_Button_c_clicked();

void on_action_Button_d_clicked();

void on_action_Button_e_clicked();

/*

void on_action_Button_equal_clicked();

void on_number_Button_clicked();

void on_action_Button_clicked();

void on_action_Button_c_clicked();

*/

private:

Ui::MyCalculatorClass ui;

};

MyCalculator.main

#include "MyCalculator.h"

#include

int main(int argc, char *argv[])

{

QApplication a(argc, argv);

MyCalculator w;

w.show();

return a.exec();

}

MyCalculator.cpp

#include "MyCalculator.h"

#include

using namespace std;

#include

#include

#include

#include

MyCalculator::MyCalculator(QWidget *parent)

: QMainWindow(parent)

{

ui.setupUi(this);

setWindowTitle(QStringLiteral("计算器"));

ui.textBrowser->setFontPointSize(28);

connect(ui.pushButton0, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton1, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton2, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton3, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton4, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton5, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton6, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton7, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton8, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton9, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton_add, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));

connect(ui.pushButton_div, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));

connect(ui.pushButton_mul, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));

connect(ui.pushButton_sub, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));

connect(ui.pushButton_right, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));

connect(ui.pushButton_left, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));

connect(ui.pushButton_dian, SIGNAL(clicked()), this, SLOT(on_comma_Button_clicked()));

connect(ui.pushButton_del, SIGNAL(clicked()), this, SLOT(on_action_Button_d_clicked()));

connect(ui.pushButton_re, SIGNAL(clicked()), this, SLOT(on_action_Button_c_clicked()));

connect(ui.pushButton_equ, SIGNAL(clicked()), this, SLOT(on_action_Button_e_clicked()));

/*

//没有优先级的计算器

connect(ui.pushButton0, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton1, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton2, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton3, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton4, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton5, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton6, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton7, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton8, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton9, SIGNAL(clicked()), this, SLOT(on_number_Button_clicked()));

connect(ui.pushButton_add, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));

connect(ui.pushButton_div, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));

connect(ui.pushButton_mul, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));

connect(ui.pushButton_sub, SIGNAL(clicked()), this, SLOT(on_action_Button_clicked()));

connect(ui.pushButton_re, SIGNAL(clicked()), this, SLOT(on_action_Button_c_clicked()));

connect(ui.pushButton_equ, SIGNAL(clicked()), this, SLOT(on_action_Button_equal_clicked()));

*/

}

void MyCalculator::on_number_Button_clicked()

{

QPushButton *btn = qobject_cast(sender());

QString number = btn->text();

QString ss = ui.textBrowser->toPlainText();

ui.textBrowser->clear();

ui.textBrowser->append(ss + number);

}

void MyCalculator::on_action_Button_clicked()//操作符

{

QPushButton *btn = qobject_cast(sender());

QString action = btn->text();

QString ss = ui.textBrowser->toPlainText();

ui.textBrowser->clear();

ui.textBrowser->append(ss + action);

}

void MyCalculator::on_comma_Button_clicked()//小数点

{

QPushButton *btn = qobject_cast(sender());

QString action = btn->text();

QString ss = ui.textBrowser->toPlainText();

ui.textBrowser->clear();

ui.textBrowser->append(ss + action);

}

void MyCalculator::on_action_Button_c_clicked()//重置输入框里的内容

{

ui.textBrowser->clear();

}

void MyCalculator::on_action_Button_d_clicked()//删除表达式中最后一个符号

{

QString ss = ui.textBrowser->toPlainText();//在一行

ss = ss.left(ss.length() - 1);

ui.textBrowser->clear();

ui.textBrowser->setText(ss);

}

bool isNum(QString ch)

{

if (ch >= '0' && ch <= '9' || ch == '.')

return true;

else

return false;

}

bool isOperate(QString ch)

{

if (ch == '+' || ch == '-' || ch == '*' || ch == '/' || ch == '(' || ch == ')' )

return true;

else

return false;

}

int level(QString ch) {//优先级设置

if(ch == '(')

return 5;

else if (ch == '*' || ch== '/')

return 4;

else if (ch == '+' || ch == '-')

return 3;

else if (ch == ')')

return 2;

}

double calcu(double a ,double b, QString c)

{

double result = 0;

if (c == '+')

result = b + a;

else if (c == '-')

result = b - a;

else if (c == '*')

result = b * a;

else if (c == '/')

result = b / a;

else

result = INT_MAX;

return result;

}

double getjieguo(QString input)

{

QStack Num;

QStack Act;

int a = input.length();

for(int i=0;i< a;i++)

{

int flag = 0;//用来判断是否是数字

int xiaoshu = 1;//用来判断是否是小数部分

double number = 0;//暂存数字

QString frist = input.left(1);

while (isNum(frist))//连续的数字转化为一个整数

{

if (frist == '.' || xiaoshu == 2)

{

number = frist.toDouble() / 10 + number;

xiaoshu = 2;

}

else

{

number = number * 10 + frist.toInt();

}

input = input.right(input.length() - 1);

frist = input.left(1);

flag = 1;

}

if (flag == 1)

Num.push(number);

if (isOperate(frist))

{

if (!Act.empty() && (level(Act.top()) > level(frist)))

{

double a = Num.pop();

double b = Num.pop();

QString c = Act.pop();

double result = calcu(a, b, c);

Num.push(result);

if (frist != ')')

Act.push(frist);

input = input.right(input.length() - 1);

frist = input.left(1);

}

else if (!Act.empty() && (level(Act.top()) <= level(frist)))

{

if (frist != '(')

Act.push(frist);

input = input.right(input.length() - 1);

frist = input.left(1);

}

else if(Act.empty())//操作符第一次入符号栈

{

Act.push(frist);

input = input.right(input.length() - 1);

frist = input.left(1);

}

}

if (frist == '=')//支持得到结果后仍可以继续运算

{

Num.clear();

Act.clear();

input = input.right(input.length() - 1);

frist = input.left(1);

}

if (i + 1 >= a)//当表达式都进栈后，只要符号栈不为空就继续执行

{

while (!Act.empty())

{

double a1 = Num.pop();

double b1 = Num.pop();

QString c1 = Act.pop();

double result = calcu(a1, b1, c1);

Num.push(result);

}

}

}

return Num.top();

}

void MyCalculator::on_action_Button_e_clicked()

{

QString input = ui.textBrowser->toPlainText();//将输入框里的内容给input

double value = getjieguo(input);//将表达式传给getjieguo来将数字和操作符分别入对应的栈

ui.textBrowser->clear();

ui.textBrowser->append(input + "=" + QString::number(value));//将结果的类型由数字转化为QString

}

/*

void MyCalculator::setnum1(int num)

{

num1 = num;

}

void MyCalculator::setnum2(int num)

{

num2 = num;

}

void MyCalculator::setflag(int f)

{

flag = f;

}

int MyCalculator::calculartor()

{

int result = 0;

if (flag == 1)

result = num1 + num2;

else if (flag == 2)

result = num1 - num2;

else if (flag == 3)

result = num1 * num2;

else if (flag == 4)

{

if (num2 == 0)

setflag(5);

else

result = num1 / num2;

}

else

result = 0;

return result;

}

void MyCalculator::on_action_Button_c_clicked()

{

ui.textBrowser->clear();

setnum1(0);

setnum2(0);

setflag(0);

}

void MyCalculator::on_number_Button_clicked()

{

QPushButton *btn = qobject_cast(sender());

QString number = btn->text();

QString ss = ui.textBrowser->toPlainText();

ui.textBrowser->clear();

ui.textBrowser->append(ss + number);

}

void MyCalculator::on_action_Button_clicked()

{

int number = ui.textBrowser->toPlainText().toInt();

setnum1(number);

QPushButton *btn = qobject_cast(sender());

QString action = btn->text();

ui.textBrowser->clear();

if (action == "+")

setflag(1);

else if (action == "-")

setflag(2);

else if (action == "*")

setflag(3);

else

setflag(4);

}

void MyCalculator::on_action_Button_equal_clicked() {

int number = ui.textBrowser->toPlainText().toInt();

setnum2(number);

int res = calculartor();

ui.textBrowser->clear();

if (flag == 5)

ui.textBrowser->append(QStringLiteral("不能除于0，请重新输入"));

else

ui.textBrowser->append(QString::number(res));

}

*/

测试

表达式

结果

2*3+6-(1+3)

8

2+3*6-(1+3)

16

2+3*6-(1.3+5/2)

16.2

说明

自己的学习笔记 ，还有一些bug没有解决；

部分代码需要优化，重构；

没有实现输入错误表达式报错功能，需要输入正确的表达式。

不支持负数计算。

支持小数，加，减，乘，除，括号运算。

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