郁闷的c小加(二)

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郁闷的C小加(二)

时间限制:1000 ms  |  内存限制:65535 KB
难度:4
描述

聪明的你帮助C小加解决了中缀表达式到后缀表达式的转换(详情请参考“郁闷的C小加(一)”),C小加很高兴。但C小加是个爱思考的人,他又想通过这种方法计算一个表达式的值。即先把表达式转换为后缀表达式,再求值。这时又要考虑操作数是小数和多位数的情况。

输入
第一行输入一个整数T,共有T组测试数据(T<10)。
每组测试数据只有一行,是一个长度不超过1000的字符串,表示这个运算式,每个运算式都是以“=”结束。这个表达式里只包含+-*/与小括号这几种符号。其中小括号可以嵌套使用。数据保证输入的操作数中不会出现负数并且小于1000000。
数据保证除数不会为0。
输出
对于每组测试数据输出结果包括两行,先输出转换后的后缀表达式,再输出计算结果,结果保留两位小数。两组测试数据之间用一个空行隔开。
样例输入
21+2=(19+21)*3-4/5=
样例输出
12+=3.001921+3*45/-=119.20
import java.util.Scanner;import java.util.Stack;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int number = scanner.nextInt();String cc = scanner.nextLine();while (number-- != 0) {String string = scanner.nextLine();Stack<Character> stack = new Stack<Character>();StringBuilder suffix = new StringBuilder("");for (int i = 0; i < string.length(); i++) {char temp = string.charAt(i);if ((temp >= '0' && temp <= '9') || temp == '.') {suffix.append(temp);} else {if (temp == '+' || temp == '-') {suffix.append(" ");if (stack.isEmpty()) {stack.push(temp);} else {char top = stack.peek();if (top == '(') {stack.push(temp);} else {while (!stack.isEmpty() && stack.peek() != '(') {suffix.append(stack.pop() + " ");}stack.push(temp);}}} else if (temp == '*' || temp == '/') {suffix.append(" ");if (stack.isEmpty()) {stack.push(temp);} else {char top = stack.peek();if (top == '+' || top == '-' || top == '(') {stack.push(temp);} else if (top == '*' || top == '/') {suffix.append(stack.pop() + " ");stack.push(temp);}}} else if (temp == '(') {stack.push(temp);} else if (temp == ')') {char top = stack.pop();while (top != '(') {suffix.append(" " + top);top = stack.pop();}} else if (temp == '=') {while (!stack.isEmpty()) {suffix.append(" " + stack.pop());}suffix.append(" " + "=");}}}System.out.println(String.valueOf(suffix).replace(" ", ""));Stack<Double> result = new Stack<Double>();String arr[] = suffix.toString().split(" ");for (int j = 0; j < arr.length; j++) {char temp = arr[j].charAt(0);double value = 0;if (temp >= '0' && temp <= '9') {value = Double.valueOf(arr[j]);result.push(value);} else if (temp == '+') {double one = result.pop();double two = result.pop();double three = one + two;result.push(three);} else if (temp == '-') {double one = result.pop();double two = result.pop();double three = two - one;result.push(three);} else if (temp == '*') {double one = result.pop();double two = result.pop();double three = one * two;result.push(three);} else if (temp == '/') {double one = result.pop();double two = result.pop();double three = two / one;result.push(three);} else if (temp == '=') {System.out.printf("%.2f\n", result.pop());}}}}}



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