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package torea; | |
public class RevPolToInfNot{ | |
public static void main(String[] args) | |
{ | |
Kattio io = new Kattio(System.in, System.out); | |
List.ArrayList<String> tokens = new List.ArrayList<String>(); | |
while(io.hasMoreTokens()){ | |
tokens.add(io.getWord()); | |
} | |
String output = getInfixReverseGraph(tokens); | |
io.println(output); | |
io.flush(); | |
io.close(); | |
} | |
public static String getInfixNotation(String query) | |
{ | |
Stack.ListStack<String> stringStack = new Stack.ListStack<String>(); | |
for(String token: query.split(" ")){ | |
if(token.equals("+")||token.equals("-")||token.equals("*")||token.equals("/")) | |
{ | |
String frst = stringStack.pop(); | |
String scnd = stringStack.pop(); | |
stringStack.push("("+scnd + token + frst+")"); | |
} else { | |
stringStack.push(token); | |
} | |
} | |
return stringStack.pop(); | |
} | |
public static String getInfixNotationSB(String query) | |
{ | |
Stack.ListStack<StringBuilder> stringStack = new Stack.ListStack<StringBuilder>(); | |
for(String token: query.split(" ")){ | |
if(token.equals("+")||token.equals("-")||token.equals("*")||token.equals("/")) | |
{ | |
StringBuilder frst = stringStack.pop(); | |
StringBuilder scnd = stringStack.pop(); | |
stringStack.push(scnd.insert(0, "(").append(token).append(frst).append(")")); | |
} else { | |
stringStack.push(new StringBuilder(token)); | |
} | |
} | |
return stringStack.pop().toString(); | |
} | |
public static boolean isOperator(String token){ | |
return token.equals("+")||token.equals("-")||token.equals("*")||token.equals("/"); | |
} | |
public static boolean isOperator(Character token){ | |
return token.equals('+')||token.equals('-')||token.equals('*')||token.equals('/'); | |
} | |
public static String getInfixReverseEvaluation(List.ArrayList<String> tokens) | |
{ | |
// Idea use one stack. | |
// Add to it. | |
// When two values have been added do operation. | |
// After doing operation use peek to check if two values are adjacent. | |
// if so repeat. | |
Stack.ListStack<String> combStack = new Stack.ListStack<String>(); | |
for( int i = tokens.size()-1; i>=0; i--){ | |
String token = tokens.get(i); | |
if(isOperator(token)) | |
{ | |
combStack.push(token); | |
} else { | |
if(isOperator(combStack.peek())){ | |
combStack.push(token); | |
} else { | |
while(!combStack.isEmpty() && !isOperator(combStack.peek())) | |
{ | |
String frst = combStack.pop(); | |
String op = combStack.pop(); | |
token = "("+token + op + frst+")"; | |
} | |
combStack.push(token); | |
} | |
} | |
} | |
return combStack.pop(); | |
} | |
public static String getInfixReverseEvaluationRecursive(List.ArrayList<String> tokens) | |
{ | |
return getExpression(tokens, tokens.size()-1).expression.toString(); | |
} | |
public static class ExpressionHolder{ | |
public StringBuilder expression; | |
public int startIndex; | |
ExpressionHolder(StringBuilder myExpression, int myStartIndex){ | |
expression = myExpression; | |
startIndex = myStartIndex; | |
} | |
} | |
public static ExpressionHolder getExpression(List.ArrayList<String> tokens, int end) | |
{ | |
StringBuilder exp = new StringBuilder("("); | |
String op = tokens.get(end); | |
StringBuilder frst; | |
int frstStart; | |
StringBuilder scnd; | |
int scndStart; | |
if(!isOperator(tokens.get(end-1))){ | |
frst = new StringBuilder(tokens.get(end-1)); | |
frstStart = end-1; | |
} | |
else{ | |
ExpressionHolder firstArgumentEH = getExpression(tokens, end-1); | |
frstStart = firstArgumentEH.startIndex; | |
frst = firstArgumentEH.expression; | |
} | |
if(!isOperator(tokens.get(frstStart - 1))){ | |
scnd = new StringBuilder(tokens.get(frstStart - 1)); | |
scndStart = frstStart - 1; | |
} | |
else{ | |
ExpressionHolder secondArgumentEH = getExpression(tokens, frstStart - 1); | |
scndStart = secondArgumentEH.startIndex; | |
scnd = secondArgumentEH.expression; | |
} | |
return new ExpressionHolder(exp.append(scnd).append(op).append(frst).append(")"), scndStart); | |
} | |
public static class Node{ | |
public int tokenId; | |
public int startIndex; | |
public Node rightChild; | |
public Node leftChild; | |
Node(int id){ | |
tokenId = id; | |
} | |
} | |
public static Node getNodes(List.ArrayList<String> tokens, int end) | |
{ | |
Node opNode = new Node(end); | |
if(!isOperator(tokens.get(end-1))){ | |
opNode.rightChild = new Node(end-1); | |
opNode.rightChild.startIndex = end-1; | |
} | |
else{ | |
opNode.rightChild = getNodes(tokens, end-1); | |
} | |
if(!isOperator(tokens.get(opNode.rightChild.startIndex - 1))){ | |
opNode.leftChild = new Node(opNode.rightChild.startIndex - 1); | |
opNode.leftChild.startIndex = opNode.rightChild.startIndex - 1; | |
} | |
else{ | |
opNode.leftChild = getNodes(tokens, opNode.rightChild.startIndex - 1); | |
} | |
opNode.startIndex = opNode.leftChild.startIndex; | |
return opNode; | |
} | |
public static void traverseGraph(StringBuilder sb, Node node, List.ArrayList<String> tokens) | |
{ | |
if(!isOperator(tokens.get(node.tokenId))) | |
{ | |
sb.append(tokens.get(node.tokenId)); | |
} | |
else | |
{ | |
sb.append("("); | |
traverseGraph(sb, node.leftChild, tokens); | |
sb.append(tokens.get(node.tokenId)); | |
traverseGraph(sb, node.rightChild, tokens); | |
sb.append(")"); | |
} | |
// return sb; | |
} | |
public static void printGraph(Kattio io, Node node, List.ArrayList<String> tokens) | |
{ | |
if(!isOperator(tokens.get(node.tokenId))) | |
{ | |
io.print(tokens.get(node.tokenId)); | |
} | |
else | |
{ | |
io.print("("); | |
printGraph(io, node.leftChild, tokens); | |
io.print(tokens.get(node.tokenId)); | |
printGraph(io, node.rightChild, tokens); | |
io.print(")"); | |
} | |
} | |
public static void printInfixReverseGraph(Kattio io,List.ArrayList<String> tokens) | |
{ | |
Node rootNode = getNodes( tokens, tokens.size()-1); | |
printGraph(io, rootNode, tokens); | |
} | |
public static String getInfixReverseGraph(List.ArrayList<String> tokens) | |
{ | |
Node rootNode = getNodes( tokens, tokens.size()-1); | |
StringBuilder sb = new StringBuilder(); | |
traverseGraph(sb, rootNode, tokens); | |
return sb.toString(); | |
} | |
} |