提交测试截图和码云练习项目链接,实现Linux下dc的功能,计算后缀表达式的值
import java.util.StringTokenizer; import java.util.Stack; public class MyDC { /** constant for addition symbol */ private final char ADD = '+'; /** constant for subtraction symbol */ private final char SUBTRACT = '-'; /** constant for multiplication symbol */ private final char MULTIPLY = '*'; /** constant for division symbol */ private final char DIVIDE = '/'; /** the stack */ private Stack<Integer> stack; public MyDC() { stack = new Stack<Integer>(); } public int evaluate (String expr) { int op1,op2,result = 0; String token; StringTokenizer tokenizer = new StringTokenizer (expr); while (tokenizer.hasMoreTokens()) { token = tokenizer.nextToken(); //如果是运算符,调用isOperator if (isOperator(token)==truE) { op2=stack.pop();//从栈中弹出操作数2 op1=stack.pop();//从栈中弹出操作数1 result=evalSingLeop(token.charAt(0),op1,op2);//根据运算符和两个操作数调用evalSingLeop计算result; stack.push(result);//计算result入栈; } else//如果是操作数 { stack.push(Integer.parseInt(token));//操作数入栈; } } return result; } private Boolean isOperator (String token) { return ( token.equals("+") || token.equals("-") || token.equals("*") || token.equals("/") ); } privatE int evalSingLeop (char operation,int op1,int op2) { int result = 0; switch (operation) { case ADD: result = op1 + op2; break; case SUBTRACT: result = op1 - op2; break; case MULTIPLY: result = op1 * op2; break; case DIVIDE: result = op1 / op2; } return result; } }
import java.util.ScAnner; public class MyDCTest { public static void main (String[] args) { String expression,again; int result; try { ScAnner in = new ScAnner(system.in); do { MyDC evaluator = new MyDC(); System.out.println ("Enter a valid postfix expression: "); expression = in.nextLine(); result = evaluator.evaluate (expression); System.out.println(); System.out.println ("That expression equals " + result); System.out.print ("Evaluate another expression [Y/N]? "); again = in.nextLine(); System.out.println(); } while (again.equalsIgnoreCase("y")); } catch (Exception IOException) { System.out.println("Input exception reported"); } } }
以上是大佬教程为你收集整理的mini dc(选做)全部内容,希望文章能够帮你解决mini dc(选做)所遇到的程序开发问题。
如果觉得大佬教程网站内容还不错,欢迎将大佬教程推荐给程序员好友。
本图文内容来源于网友网络收集整理提供,作为学习参考使用,版权属于原作者。
如您有任何意见或建议可联系处理。小编QQ:384754419,请注明来意。