四则运算4（Android版）
结组照：
下载地址：https://files.cnblogs.com/files/wangjianly/WangJian.apk
在上次四则运算的基础上，将编写的四则运算发布成安卓版，具体实现功能如下：
1：是否有除数参与运算
2：是否有括号参与运算
3：产生的数值的范围（从1开始）
4：设定出题的数量
解决办法：
这个安卓的程序主要有两个界面，一个是对用户输入的要求进行判断，然后根据要求进行生成随机四则运算。另一个是答题界面。
运行结果截图如下：
源代码如下：
第一个布局代码;
package com.wwwjjj.wangjian;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioGroup;
public class MainActivity extends Activity implements OnClickListener {
private RadioGroup chufa;
private RadioGroup kouhao;
private EditText range;
private EditText exp_num;
private Button btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
chufa = (RadioGroup) findViewById(R.id.rg_chufa);
kouhao = (RadioGroup) findViewById(R.id.rg_kuohao);
range = (EditText) findViewById(R.id.et_range);
exp_num = (EditText) findViewById(R.id.et_exp_num);
btn = (Button) findViewById(R.id.btn_next);
btn.setOnClickListener(this);
}
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
int chufaId = chufa.getCheckedRadioButtonId();
int kuohaoId = kouhao.getCheckedRadioButtonId();
Boolean haveChufa = false, haveKuohao = false;
if (chufaId == R.id.chuafa_yes)
haveChufa = true;
if (kuohaoId == R.id.kuohao_yes)
haveKuohao = true;
int r = Integer.valueOf(range.getText().toString());
int en = Integer.valueOf(exp_num.getText().toString());
Intent intent =new Intent(MainActivity.this,SolutionActivity.class);
Bundle bundle=new Bundle();
bundle.putBoolean("kuohao", haveKuohao);
bundle.putBoolean("chufa", haveChufa);
bundle.putInt("range", r);
bundle.putInt("exp_num", en);
intent.putExtras(bundle);
startActivity(intent);
}
}
第二个运行程序界面：
package com.wwwjjj.wangjian;
import java.math.BigDecimal;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class SolutionActivity extends Activity implements OnClickListener{
private TextView exp;
private TextView tv_num;
private EditText tv_ans;
private Button okBtn;
private Button nextBtn;
private String expString;
private Test test;
private boolean haveChu;
private boolean haveKuohao;
private int range;
private int exp_num;
int chu=2,kuohao=2;
double ans;
private double result2;
private double result;
private Integer myans;
private int count=1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_solution);
haveKuohao=getIntent().getBooleanExtra("kuohao", haveKuohao);
haveChu=getIntent().getBooleanExtra("chufa", haveChu);
if(haveChu)chu=1;
if(haveKuohao)kuohao=1;
range=getIntent().getIntExtra("range", range);
exp_num=getIntent().getIntExtra("exp_num", exp_num);
exp=(TextView)findViewById(R.id.tv_exp);
tv_num=(TextView)findViewById(R.id.tv_num);
tv_ans=(EditText)findViewById(R.id.et_ans);
okBtn=(Button)findViewById(R.id.okBtn);
nextBtn=(Button)findViewById(R.id.nextBtn);
okBtn.setOnClickListener(this);
nextBtn.setOnClickListener(this);
//从java类中取出表达式到expString中
tv_num.setText("第"+count+++"题：");
test=new Test();
expString= test.shu(chu,kuohao,range);
//将表达式显示到exp （exp.setText(表达式)）
exp.setText(expString+"=");
result2 = test.computeWithStack(expString);
BigDecimal bg2=new BigDecimal(result2);
result=bg2.setScale(2,BigDecimal.ROUND_HALF_UP).doubleValue();
}
@Override
public void onClick(View v0) {
// TODO Auto-generated method stub
if(v0==okBtn){
//从tv_ans中取出答案
//判断答案是否正确
//显示判断结果
myans=Integer.valueOf(tv_ans.getText().toString());
if(myans==result){
Toast.makeText(SolutionActivity.this, "回答正确", 0).show();
}else{
Toast.makeText(SolutionActivity.this, "回答错误", 0).show();
}
}else if(v0==nextBtn){
tv_ans.setText("");
if(count>exp_num) finish();
//从java类中取出表达式
//将表达式显示到exp （exp.setText(表达式)）
tv_num.setText("第"+count+++"题：");
expString= test.shu(chu,kuohao,range);
//将表达式显示到exp （exp.setText(表达式)）
exp.setText(expString+"=");
result2 = test.computeWithStack(expString);
BigDecimal bg2=new BigDecimal(result2);
result=bg2.setScale(2,BigDecimal.ROUND_HALF_UP).doubleValue();
}
}
}
java文件：
package com.wwwjjj.wangjian;
//import java.awt.SystemColor;
import java.util.HashMap;
import java.util.Map;
import java.util.Stack;
import java.util.StringTokenizer;
import java.util.regex.Pattern;
public class Test {
public double computeWithStack(String computeExpr) {
//把表达式用运算符、括号分割成一段一段的，并且分割后的结果包含分隔符
StringTokenizer tokenizer = new StringTokenizer(computeExpr, "+-*/()", true);
Stack<Double> numStack = new Stack<Double>(); //用来存放数字的栈
Stack<Operator> operStack = new Stack<Operator>(); //存放操作符的栈
Map<String, Operator> computeOper = this.getComputeOper(); //获取运算操作符
String currentEle; //当前元素
while (tokenizer.hasMoreTokens()) {
currentEle = tokenizer.nextToken().trim(); //去掉前后的空格
if (!"".equals(currentEle)) { //只处理非空字符
if (this.isNum(currentEle)) { //为数字时则加入到数字栈中
numStack.push(Double.valueOf(currentEle));
} else { //操作符
Operator currentOper = computeOper.get(currentEle);//获取当前运算操作符
if (currentOper != null) { //不为空时则为运算操作符
while (!operStack.empty() && operStack.peek().priority() >= currentOper.priority()) {
compute(numStack, operStack);
}
//计算完后把当前操作符加入到操作栈中
operStack.push(currentOper);
} else {//括号
if ("(".equals(currentEle)) { //左括号时加入括号操作符到栈顶
operStack.push(Operator.BRACKETS);
} else { //右括号时, 把左括号跟右括号之间剩余的运算符都执行了。
while (!operStack.peek().equals(Operator.BRACKETS)) {
compute(numStack, operStack);
}
operStack.pop();//移除栈顶的左括号
}
}
}
}
}
// 经过上面代码的遍历后最后的应该是nums里面剩两个数或三个数，operators里面剩一个或两个运算操作符
while (!operStack.empty()) {
compute(numStack, operStack);
}
return numStack.pop();
}
/**
* 判断一个字符串是否是数字类型
* @param str
* @return
*/
private boolean isNum(String str) {
String numRegex = "^\\d+(\\.\\d+)?$"; //数字的正则表达式
return Pattern.matches(numRegex, str);
}
/**
* 获取运算操作符
* @return
*/
private Map<String, Operator> getComputeOper() {
return new HashMap<String, Operator>() { // 运算符
private static final long serialVersionUID = 7706718608122369958L;
{
put("+", Operator.PLUS);
put("-", Operator.MINUS);
put("*", Operator.MULTIPLY);
put("/", Operator.DIVIDE);
}
};
}
private void compute(Stack<Double> numStack, Stack<Operator> operStack) {
Double num2 = numStack.pop(); // 弹出数字栈最顶上的数字作为运算的第二个数字
Double num1 = numStack.pop(); // 弹出数字栈最顶上的数字作为运算的第一个数字
Double computeResult = operStack.pop().compute(
num1, num2); // 弹出操作栈最顶上的运算符进行计算
numStack.push(computeResult); // 把计算结果重新放到队列的末端
}
/**
* 运算符
*/
private enum Operator {
/**
* 加
*/
PLUS {
@Override
public int priority() {
return 1;
}
@Override
public double compute(double num1, double num2) {
return num1 + num2;
}
},
/**
* 减
*/
MINUS {
@Override
public int priority() {
return 1;
}
@Override
public double compute(double num1, double num2) {
return num1 - num2;
}
},
/**
* 乘
*/
MULTIPLY {
@Override
public int priority() {
return 2;
}
@Override
public double compute(double num1, double num2) {
return num1 * num2;
}
},
/**
* 除
*/
DIVIDE {
@Override
public int priority() {
return 2;
}
@Override
public double compute(double num1, double num2) {
return num1 / num2;
}
},
/**
* 括号
*/
BRACKETS {
@Override
public int priority() {
return 0;
}
@Override
public double compute(double num1, double num2) {
return 0;
}
};
/**
* 对应的优先级
* @return
*/
public abstract int priority();
/**
* 计算两个数对应的运算结果
* @param num1 第一个运算数
* @param num2 第二个运算数
* @return
*/
public abstract double compute(double num1, double num2);
}
//符号函数
//-------------------------------------------------------------
static String fuhao(int chu)
{
String fu;
int num_3;
if (chu == 1)
{
num_3 = ((int)(Math.random() * 100)) % 4;
if (num_3 == 0) fu = "+";
else if (num_3 == 1) fu = "-";
else if (num_3 == 2) fu = "*";
else fu = "/";
return fu;
}
else
{
num_3 = ((int)(Math.random()*20)) % 2;
if (num_3 == 0) fu = "+";
else fu = "-";
return fu;
}
}
//分数函数
//-------------------------------------------------------------
static String fenshu()
{
int a1 = 0, b1 = 0, a2 = 0, b2 = 0;
a1 = ((int)(Math.random()*(97)));
b1 = ((int)(Math.random()*100 - a1)) + a1 + 1;
a2 = ((int)(Math.random()* (97)));
b2 = ((int)(Math.random()* (100 - a2))) + a2 + 1;
String first_a1, second_b1;
String first_a2, second_b2;
first_a1 = String.valueOf(a1);
second_b1 = String.valueOf(b1);
first_a2 = String.valueOf(a2);
second_b2 = String.valueOf(b2);
String all1 = "";
//随机产生四则运算符
int fu = 0;
fu = ((int)(Math.random()*100)) % 2;
if (fu == 0)
{
all1 = "(" + first_a1 + "/" + second_b1 + ")" + "+" + "(" + first_a2 + "/" + second_b2 + ")" ;
}
else if (fu == 1)
{
all1 = "(" + first_a1 + "/" + second_b1 + ")" + "-" + "(" + first_a2 + "/" + second_b2 + ")" ;
}
else if (fu == 2)
{
all1 = "(" + first_a1 + "/" + second_b1 + ")" + "*" + "(" + first_a2 + "/" + second_b2 + ")" ;
}
else
{
all1 = "(" + first_a1 + "/" + second_b1 + ")" + "/" + "(" + first_a2 + "/" + second_b2 + ")" ;
}
return all1;
}
/*private static String to_String(int b1) {
// TODO Auto-generated method stub
return null;
}*/
//运算函数
//-------------------------------------------------------------
String shu(int chu, int kuohao, int range)
{
int num_1, num_2;
int geshu;
int calculate_kuohao=3;
String str_first, str_second;
String all = "";
int ch1;
geshu = ((int)(Math.random()*(4)) + 2);
for (int i = 1; i <= geshu; i++)
{
num_1 = ((int)(Math.random()* (range))) + 1;
str_first = String.valueOf(num_1);
num_2 = ((int)(Math.random()*(range))) + 1;
str_second = String.valueOf(num_2);
if ((kuohao == 1)&&(calculate_kuohao!=0))
{
ch1 = ((int)(Math.random()*(4))) + 1;
switch (ch1){
case 1:
{
if (all == "") { all = str_first + fuhao(chu) + str_second; }
else { all = str_first + fuhao(chu) + all; }
}break;
case 2:
{
if (all == "") { all = str_second + fuhao(chu) + str_first; }
else { all = all + fuhao(chu) + str_first; }
}break;
case 3:
{
if (all == "") { all = "(" + str_first + fuhao(chu) + str_second + ")"; }
else { all = "(" + str_first + fuhao(chu) + all + ")"; }
calculate_kuohao = calculate_kuohao - 1;
}break;
case 4:
{
if (all == ""){ all = "(" + str_second + fuhao(chu) + str_first + ")"; }
else { all = "(" + all + fuhao(chu) + str_first + ")"; }
calculate_kuohao = calculate_kuohao - 1;
}break;
}
}
else
{
ch1 = ((int)(Math.random()*(2))) + 1;
switch (ch1){
case 1:
{
if (all == "") { all = str_first + fuhao(chu) + str_second; }
else { all = str_first + fuhao(chu) + all; }
}break;
case 2:
{
if (all == "") { all = str_second + fuhao(chu) + str_first; }
else { all = all + fuhao(chu) + str_first; }
}break;
}
}
}
return all ;
}
}
