Java 获取反波兰表达式
获取反波兰表达式
实例源码：
源代码：
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// 来 自 时代Java - N o w J a v a . c o m2
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//package com.nowjava;4
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import java.util.ArrayList;6
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import java.util.List;8
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import java.util.Stack;11
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public class Main {14
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public static void main(String[] argv) throws Exception {16
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String normalExpression = "nowjava.com";18
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System.out.println(getInversePolandExpression(normalExpression));20
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}22
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static private List<String> getInversePolandExpression(25
/* 26
*来 自27
nowjava - 时代Java28
*/29
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String normalExpression) {31
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List<String> inversePolandExpression = new ArrayList<String>();33
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char[] normalChararray = (normalExpression + "$").toCharArray();35
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// 37
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Stack<String> signStack = new Stack<String>();39
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List<Stack<String>> signStackList = new ArrayList<Stack<String>>();41
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signStackList.add(signStack);43
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// 45
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int level = 0;47
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int pointPosition = 0;50
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double tempNumber = 0;52
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boolean isInInteger = true;54
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for (int i = 0; i < normalChararray.length; i++) {57
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char tempChar = normalChararray[i];59
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// 61
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if (tempChar >= '0' && tempChar <= '9') {63
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// 65
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if (isInInteger) {67
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tempNumber = tempNumber * 10 + (int) (tempChar - 48);69
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}71
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// ?73
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else {75
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tempNumber += (double) (tempChar - 48)77
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* Math.pow(0.1, i - pointPosition);79
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}81
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}84
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// ?86
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else if (tempChar == '.') {88
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isInInteger = false;90
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pointPosition = i;92
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}94
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// 96
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else if (tempChar == '+' || tempChar == '-' || tempChar == '*'98
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|| tempChar == '/' || tempChar == '$') {100
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// 102
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isInInteger = true;104
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// ?106
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if (tempNumber > 0) {108
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inversePolandExpression.add(String.valueOf(tempNumber));110
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}112
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// 0114
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tempNumber = 0;116
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// ???118
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if ((tempChar == '+') || (tempChar == '-')120
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|| tempChar == '$') {122
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while (!signStackList.get(level).isEmpty()) {125
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// 127
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inversePolandExpression.add(signStackList129
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.get(level).pop());131
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}133
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}135
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// ?137
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signStackList.get(level).push(tempChar + "");140
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} else if (tempChar == '(') {143
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signStack = new Stack<String>();145
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signStackList.add(signStack);147
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level++;149
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} else if (tempChar == ')') {151
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// 153
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isInInteger = true;155
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// ?157
/**代码未完, 请加载全部代码(NowJava.com).**/执行结果：
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