10.11
今天大概的实现四则运算的全部功能，但是其中仍然有很多不足的地方。
先来看看代码
package test; import java.util.*; import sizeyunsuan1.FormulaCalculator; public class suan2 { public static String P[]=new String[100];//题目 public int Q[]=new int[100]; public static int J[]=new int[100];//错题 public static int anwser[]=new int[1000];//答案 public int Temp[]=new int[100]; public static void main(String[] args) { // TODO 自动生成的方法存根 Scanner cin=new Scanner(System.in); suan2 a=new suan2(); int k=0;//错误题数 int temp=1; int N=30;//出题个数 while(temp==1) { System.out.println("****************************************\r\n"+ "1、参数设置\r\n" + "2、小学二年级口算题\r\n" + "3、小学三年级口算题\r\n" + "4、小学四年级口算题\r\n" + "5、错题集\r\n" + "请输入要操作的序号：\r\n"+ "****************************************"); int num=cin.nextInt(); switch(num) { case 1: System.out.println("请输入出题个数："); N=cin.nextInt(); //System.out.println("输入q回到主菜单"); //String ch=cin.next(); break; case 2: case 3: case 4: for(int i=0;i<N;i++) { String A=a.string(a,num,i); System.out.println(i+1+","+A+"="); anwser[i]=FormulaCalculator.getResult(A); int anwser1=cin.nextInt(); if(anwser1==anwser[i]) { System.out.println("正确！！！"); } else if(anwser1!=anwser[i]) {System.out.println("错误，已记录在错题本！");J[k]=i;++k;} } int trues=(N-k)/N; System.out.println("正确率："+trues*100+"%"); //System.out.println("输入q回到主菜单"); //String ch1=cin.next(); break; case 5: for(int i=0;i<k;i++) { System.out.println(P[J[i]]); int anwser2=cin.nextInt(); if(anwser2==anwser[i]) { System.out.println("正确！！！"); } else if(anwser2!=anwser[i]) {System.out.println("错误");} } } System.out.println("输入1继续运行，输入0退出系统"); temp=cin.nextInt(); } } public String string(suan2 a,int n,int i)//查重 { String A; int Temp=0; for(;;) { A=a.suanf(n, i); for(int j=0;j<i;i++) { if(A.equals(a.P[j])) { Temp=1; break; } } if(Temp==0) break; } return A; } public int random1(int a)//生成随机数 { Random ran1 = new Random(); return (ran1.nextInt(a)+1); } public char random2()//生成随机符号 { Random ran1 = new Random(); int a=ran1.nextInt(4); char b; if(a==1) b='+'; else if(a==2) b='-'; else if(a==3) b='*'; else b='/'; return b; } /*public int answer1(int a,char b,int c) { int P; if(b=='+') P=a+b; else if(b=='-') P=a-b; else if(b=='*') P=a*b; else P=a/b; return P; }*/ public String suanf(int AB,int AB1)//生成题目，AB为年级数，AB1为题数 { int n; if(AB==2) n=100; else if(AB==3) n=1000; else n=1000; int a[]=new int[5]; char b[]=new char[4]; for(int i=0;i<5;i++) { a[i]=random1(n); } for(int i=0;i<4;i++) { b[i]=random2(); } String A=String.valueOf(a[0])+String.valueOf(b[0]); String B=String.valueOf(a[1])+String.valueOf(b[1]); String C=String.valueOf(a[2])+String.valueOf(b[2]); String D=String.valueOf(a[3])+String.valueOf(b[3]); String E=String.valueOf(a[4]); int rand=random1(2); if(AB==2) P[AB1]=A+E; else if(AB==3) if(rand==1) { P[AB1]= A+B+C+E;} else if(rand==2) { P[AB1]=A+B+E; } if(AB==4) { int a1=random1(5); int a2=random1(5); while(a1==a2||a1==5||a2==1||(a1==1&&a2==5)) { a1=random1(5); a2=random1(5); } if(a1>a2) {int a3=a2;a2=a1;a1=a3;} switch(a1) { case 1:A=String.valueOf('(')+A;break; case 2:B=String.valueOf('(')+B;break; case 3:C=String.valueOf('(')+C;break; case 4:D=String.valueOf('(')+D;break; } switch(a2) { case 2:B=String.valueOf(a[1])+String.valueOf(')')+String.valueOf(b[1]);break; case 3:C=String.valueOf(a[2])+String.valueOf(')')+String.valueOf(b[2]);break; case 4:D=String.valueOf(a[3])+String.valueOf(')')+String.valueOf(b[3]);break; case 5:E=String.valueOf(a[4])+String.valueOf(')');break; } P[AB1]=A+B+C+D+E; } return P[AB1]; } //此下为栈计算 private static boolean isRightFormat = true; public static int getResult(String formula){ int returnValue = 0; try{ returnValue = (int) doAnalysis(formula); }catch(NumberFormatException nfe){ System.out.println("公式格式有误，请检查:" + formula); }catch(Exception e){ e.printStackTrace(); } if(!isRightFormat){ System.out.println("公式格式有误，请检查:" + formula); } return returnValue; } private static double doAnalysis(String formula){ double returnValue = 0; LinkedList<Integer> stack = new LinkedList<Integer>(); int curPos = 0; String beforePart = ""; String afterPart = ""; String calculator = ""; isRightFormat = true; while(isRightFormat&&(formula.indexOf('(') >= 0||formula.indexOf(')') >= 0)){ curPos = 0; for(char s : formula.toCharArray()){ if(s == '('){ stack.add(curPos); }else if(s == ')'){ if(stack.size() > 0){ beforePart = formula.substring(0, stack.getLast()); afterPart = formula.substring(curPos + 1); calculator = formula.substring(stack.getLast() + 1, curPos); formula = beforePart + doCalculation(calculator) + afterPart; stack.clear(); break; }else{ System.out.println("有未关闭的右括号！"); isRightFormat = false; } } curPos++; } if(stack.size() > 0){ System.out.println("有未关闭的左括号！"); break; } } if(isRightFormat){ returnValue = doCalculation(formula); } return returnValue; } private static double doCalculation(String formula) { ArrayList<Double> values = new ArrayList<Double>(); ArrayList<String> operators = new ArrayList<String>(); int curPos = 0; int prePos = 0; int minus = 0; for (char s : formula.toCharArray()) { if ((s == '+' || s == '-' || s == '*' || s == '/') && minus !=0 && minus !=2) { values.add(Double.parseDouble(formula.substring(prePos, curPos).trim())); operators.add("" + s); prePos = curPos + 1; minus = minus +1; }else{ minus =1; } curPos++; } values.add(Double.parseDouble(formula.substring(prePos).trim())); char op; for (curPos = 0; curPos <= operators.size() - 1; curPos++) { op = operators.get(curPos).charAt(0); switch (op) { case '*': values.add(curPos, values.get(curPos) * values.get(curPos + 1)); values.remove(curPos + 1); values.remove(curPos + 1); operators.remove(curPos); curPos = -1; break; case '/': values.add(curPos, values.get(curPos) / values.get(curPos + 1)); values.remove(curPos + 1); values.remove(curPos + 1); operators.remove(curPos); curPos = -1; break; } } for (curPos = 0; curPos <= operators.size() - 1; curPos++) { op = operators.get(curPos).charAt(0); switch (op) { case '+': values.add(curPos, values.get(curPos) + values.get(curPos + 1)); values.remove(curPos + 1); values.remove(curPos + 1); operators.remove(curPos); curPos = -1; break; case '-': values.add(curPos, values.get(curPos) - values.get(curPos + 1)); values.remove(curPos + 1); values.remove(curPos + 1); operators.remove(curPos); curPos = -1; break; } } return values.get(0).doubleValue(); } }
其中设计到很多知识都是未曾接触过，所以这个小系统写下来真的很不容易。
