package compiling;
import java.util.Random;
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.lang.StringBuilder;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Scanner;
import java.util.Stack;
/**
*
* @author weifeng
*/
public class Compiling {
//private static LinkedList<String> operators=new LinkedList<>(); //用于记录操作符
//private static LinkedList<String> output=new LinkedList<>();//用来记录输出
//private static StringBuilder sb=new StringBuilder();//用来记录后缀表达式
/**
* @param args the command line arguments
*/
static String path1 = "C:\\Users\\weifeng\\Desktop\\结果.txt";
static String path = "C:\\Users\\weifeng\\Desktop\\算术表达式.txt";
static String path2 = "C:\\Users\\weifeng\\Desktop\\错误.txt";
static String path3 = "C:\\Users\\weifeng\\Desktop\\检查结果.txt";
static int n=0;
public static void main(String[] args) throws IOException {
while(true){
System.out.println(" ");
System.out.println("请做出以下选择：");
System.out.println("1，生成40道正确的算术表达式");
System.out.println("2，生成40道错误的算术表达式");
System.out.println("3，将算术表达式中缀转后缀");
System.out.println("4，判断错误的正确表达式");
System.out.println("0，退出");
System.out.println(" ");
int x;
System.out.print("你的选择是：");
Scanner input = new Scanner(System.in);
x = input.nextInt();
switch(x){
case 1:
{
FileWriter fc =new FileWriter(path);
//FileWriter fcc =FileWriter(fc);
//BufferedWriter fccc =BufferedWriter(fcc);
int i =0;
while(i<=40){
i++;
String CC ="";
String DD =getnumberset(CC);
System.out.println(DD);
fc.write(DD+"\r\n");
//fccc.flush();
}
fc.close();
break;
}
case 2:
{
FileWriter fe =new FileWriter(path2);
int i =0;
while(i<=40){
i++;
String MM ="";
String NN =wrong(MM);
System.out.println(NN);
fe.write(NN+"\r\n");
//fccc.flush();
}
fe.close();
break;
}
case 3:
changefirst();
break;
case 4:
analysefirst();
break;
case 0:
return;
default:
break;
}
}
//analysefirst();
}
public static String getnumberset(String AA){ //随机生成算术表达式
String numberset="";
String BB="";
String[] A ={"+","-","*","/"};
//生成最简单的运算式子
int max=1000;
int min=0;
Random random =new Random();
//随机生成1000以内的数字
n++;
if(n<6){
boolean flag =random.nextBoolean();
int number =random.nextInt(max)%(max-min+1)+min;
//int number2 =random.nextInt(max)%(max-min+1)+min;
int rand =(int)(Math.random()*A.length);
if (flag==true){
numberset ="("+String.valueOf(number)+String.valueOf(A[rand])+getnumberset(BB)+")";
return numberset;
}
else{
numberset =String.valueOf(number)+String.valueOf(A[rand])+getnumberset(BB);
return numberset;
}}
else{
n=0;
int rands =(int)(Math.random()*A.length);
int number1 =random.nextInt(max)%(max-min+1)+min;
int number2 =random.nextInt(max)%(max-min+1)+min;
boolean flag1 =random.nextBoolean();
if(flag1==true){
numberset =String.valueOf(number1)+String.valueOf(A[rands])+String.valueOf(number2);
return numberset;}
else{
numberset ="("+String.valueOf(number1)+String.valueOf(A[rands])+String.valueOf(number2)+")";
return numberset;
}
}
//number1=String.valueOf(rands);
}
public static void changefirst() throws FileNotFoundException, IOException{ //从文件中读取并将中缀转后缀写入新的文件
FileWriter fw = new FileWriter(path1);
File file = new File(path);
FileReader reader = new FileReader(file);
BufferedReader breader = new BufferedReader(reader);
String C = "";
while((C = breader.readLine())!=null){
System.out.println(C);
System.out.print("中缀转后缀为：");
System.out.println(changesecond(C));
fw.write("中缀："+C+"\r\n");
fw.write("后缀："+changesecond(C)+"\r\n");
}
breader.close();
fw.close();
}
public static String wrong(String EE){//随机生成错误的正确表达式
String numberset="";
String FF="";
String[] A ={"+","-","*","/","(",")","++","+-","**","/*","+*"};
//生成最简单的运算式子
int max=1000;
int min=0;
Random random =new Random();
//随机生成1000以内的数字
n++;
if(n<6){
boolean flag =random.nextBoolean();
int number =random.nextInt(max)%(max-min+1)+min;
//int number2 =random.nextInt(max)%(max-min+1)+min;
int rand =(int)(Math.random()*A.length);
if (flag==true){
numberset ="("+String.valueOf(number)+String.valueOf(A[rand])+wrong(FF)+")";
return numberset;
}
else{
numberset =String.valueOf(number)+String.valueOf(A[rand])+wrong(FF);
return numberset;
}}
else{
n=0;
int rands =(int)(Math.random()*A.length);
int number1 =random.nextInt(max)%(max-min+1)+min;
int number2 =random.nextInt(max)%(max-min+1)+min;
boolean flag1 =random.nextBoolean();
if(flag1==true){
numberset =String.valueOf(number1)+String.valueOf(A[rands])+String.valueOf(number2);
return numberset;}
else{
numberset ="("+String.valueOf(number1)+String.valueOf(A[rands])+String.valueOf(number2)+")";
return numberset;
}
}
}
public static void analysefirst() throws FileNotFoundException, IOException{ //分析错误的算术表达式
File a =new File(path2);
FileReader areader = new FileReader(a);
BufferedReader abreader = new BufferedReader(areader);
String W ="";
while(( W= abreader.readLine())!=null){
int rcount =0; //右括号数
int lcount =0; //
System.out.println(W);
System.out.println("判断：");
for(int i=0;i<W.length();i++){
if(i<W.length()-1){
if(W.charAt(i)=='('){
lcount=lcount +1;
if(W.charAt(i+1)==')'){System.out.println("第 "+i+" 字符 ( 后缺少运算表达式");}}
if(W.charAt(i)==')'){
rcount=rcount +1;
if(rcount>lcount){System.out.println("第 "+i+" 字符括号 ) 与前面括号不匹配");}
if(W.charAt(i+1)!='-'&& W.charAt(i+1)!='+'&& W.charAt(i+1)!='/'&& W.charAt(i+1)!='*'&&W.charAt(i+1)!='('&& W.charAt(i+1)!=')'){
System.out.println("第 "+i+" 个字符 ） 后不能直接出现数字");
}
if(W.charAt(i+1)=='('){System.out.println("第 "+i+" 个字符 ） 后不能直接出现 (");}
}
if(W.charAt(i)=='+'||W.charAt(i)=='-'||W.charAt(i)=='/'||W.charAt(i)=='*'||W.charAt(i)=='('){
if(W.charAt(i+1)=='+'||W.charAt(i+1)=='-'||W.charAt(i+1)=='/'||W.charAt(i+1)=='*'){
System.out.println("第 "+i+" 字符运算符号后缺少运算值");
}
}
if(W.charAt(i)!='-'&& W.charAt(i)!='+'&& W.charAt(i)!='/'&& W.charAt(i)!='*'&&W.charAt(i)!='('&& W.charAt(i+1)!=')'){
if(W.charAt(i+1)=='(')
System.out.println("第 "+i+" 数值后面不能直接添加 ( ");
}
}
if(i==W.length()-1){
if(W.charAt(i)=='('){lcount++;}
if(W.charAt(i)==')'){rcount++;}
if(W.charAt(i)=='+'||W.charAt(i)=='-'||W.charAt(i)=='/'||W.charAt(i)=='*'){
System.out.println("最后一个运算符号右边缺少运算值");
}
if(lcount!=rcount)
System.out.println("最后一个括号与前面不匹配");
}
}
}
abreader.close();
}
public static String changesecond(String exp) throws IOException{
Stack<Character> s = new Stack<Character>(); // 要输出的后缀表达式字符串
String suffix = "";
int length = exp.length(); // 输入的中缀表达式的长度
for (int i = 0; i < length; i++) {
char temp;
char ch = exp.charAt(i);
switch (ch) {
case ' ':
break;
case '(':
s.push(ch);
break;
case '+':
case '-':
while (s.size() != 0) {
temp = s.pop();
if (temp == '(') {
s.push('(');
break;
}
suffix += temp;
}
s.push(ch);
break;
case '*':
case '/':
while (s.size() != 0) {
temp = s.pop();
if (temp == '+' || temp == '-' || temp == '(') {
s.push(temp);
break;
}
else {suffix += temp; }
}
s.push(ch);
break;
case ')':
while (!s.isEmpty()) {
temp = s.pop();
if (temp == '(') {
break;
}
else { suffix += temp;}
}
break;
default:
suffix +=ch;
if(i+1<exp.length()){
char nu=exp.charAt(i+1);
if(nu == '-'||nu=='+'||nu=='/'||nu=='*'){
suffix +=" ";break;}
else break;
}
}
}
while (s.size() != 0) {
suffix += s.pop();
}
return suffix;
}
}
运行结果：
图片1.png
图片2.png
图片3.png
图片4.png
图片5.png
图片6.png
图片7.png
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