C++結(jié)合QT實現(xiàn)帶有優(yōu)先級的計算器功能
更新時間：2021年01月05日 17:13:30 作者：ruokey_1
這篇文章主要介紹了C++結(jié)合QT實現(xiàn)帶有優(yōu)先級的計算器,本文通過實例代碼給大家介紹的非常詳細(xì)，對大家的學(xué)習(xí)或工作具有一定的參考借鑒價值，需要的朋友可以參考下
代碼
MyCalculator.h
#pragma once
#include <QtWidgets/QMainWindow>
#include <QStack>
#include <QString>
#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 <QtWidgets/QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MyCalculator w;
w.show();
return a.exec();
}
MyCalculator.cpp
#include "MyCalculator.h"
#include<iostream>
using namespace std;
#include<stack>
#include<vector>
#include<cstdlib>
#include<limits.h>
MyCalculator::MyCalculator(QWidget *parent)
: QMainWindow(parent)
{
ui.setupUi(this);
setWindowTitle(QStringLiteral("計算器"));
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()));
/*
//沒有優(yōu)先級的計算器
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<QPushButton*>(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<QPushButton*>(sender());
QString action = btn->text();
QString ss = ui.textBrowser->toPlainText();
ui.textBrowser->clear();
ui.textBrowser->append(ss + action);
}
void MyCalculator::on_comma_Button_clicked()//小數(shù)點(diǎn)
{
QPushButton *btn = qobject_cast<QPushButton*>(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()//重置輸入框里的內(nèi)容
{
ui.textBrowser->clear();
}
void MyCalculator::on_action_Button_d_clicked()//刪除表達(dá)式中最后一個符號
{
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) {//優(yōu)先級設(shè)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<double> Num;
QStack<QString> Act;
int a = input.length();
for(int i=0;i< a;i++)
{
int flag = 0;//用來判斷是否是數(shù)字
int xiaoshu = 1;//用來判斷是否是小數(shù)部分
double number = 0;//暫存數(shù)字
QString frist = input.left(1);
while (isNum(frist)) //連續(xù)的數(shù)字轉(zhuǎn)化為一個整數(shù)
{
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()) //操作符第一次入符號棧
{
Act.push(frist);
input = input.right(input.length() - 1);
frist = input.left(1);
}
}
if (frist == '=')//支持得到結(jié)果后仍可以繼續(xù)運(yùn)算
{
Num.clear();
Act.clear();
input = input.right(input.length() - 1);
frist = input.left(1);
}
if (i + 1 >= a) //當(dāng)表達(dá)式都進(jìn)棧后，只要符號棧不為空就繼續(xù)執(zhí)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();//將輸入框里的內(nèi)容給input
double value = getjieguo(input);//將表達(dá)式傳給getjieguo來將數(shù)字和操作符分別入對應(yīng)的棧
ui.textBrowser->clear();
ui.textBrowser->append(input + "=" + QString::number(value));//將結(jié)果的類型由數(shù)字轉(zhuǎn)化為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<QPushButton*>(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<QPushButton*>(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，請重新輸入"));
else
ui.textBrowser->append(QString::number(res));
}
*/
測試
| 表達(dá)式 | 結(jié)果 |
|---|---|
| 2*3+6-(1+3) | 8 |
| 2+3*6-(1+3) | 16 |
| 2+3*6-(1.3+5/2) | 16.2 |
說明
- 自己的學(xué)習(xí)筆記 ，還有一些bug沒有解決；
- 部分代碼需要優(yōu)化，重構(gòu)；
- 沒有實現(xiàn)輸入錯誤表達(dá)式報錯功能，需要輸入正確的表達(dá)式。
- 不支持負(fù)數(shù)計算。
- 支持小數(shù)，加，減，乘，除，括號運(yùn)算。
到此這篇關(guān)于C++結(jié)合QT實現(xiàn)帶有優(yōu)先級的計算器的文章就介紹到這了,更多相關(guān)C++實現(xiàn)計算器內(nèi)容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！
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