JavaExercises/Experiments/InfixToPostfix.java at master · biblelamp/JavaExercises · GitHub

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import java.util.List;

import java.util.LinkedList;

import java.util.ArrayList;

class InfixToPostfix {

static List<String> infixToPostfix(String expression) {

List<String> result = new ArrayList<>();

LinkedList<Character> stackOper = new LinkedList<>();

for (int i = 0; i < expression.length(); i++) {

char c = expression.charAt(i);

if (precedence(c) > 0) {

while (!stackOper.isEmpty() && precedence(stackOper.peek()) >= precedence(c)) {

result.add(stackOper.pop().toString());

}

stackOper.push(c);

} else if (c == ')') {

char x = stackOper.pop();

while (x != '('){

result.add(Character.toString(x));

x = stackOper.pop();

}

} else if (c == '(') {

stackOper.push(c);

} else {

// character is neither operator nor parentheses

result.add(Character.toString(c));

}

System.out.print(result);

System.out.println(stackOper);

}

while (stackOper.size() > 0) {

result.add(stackOper.pop().toString());

}

return result;

}

private static int precedence(char c) {

switch (c) {

case '+':

case '-':

return 1;

case '*':

case '/':

return 2;

case '^':

return 3;

}

return -1;

}

public static void main(String[] args) {

System.out.println(infixToPostfix("2*((1+1)"));

}

JavaExercises/Experiments/InfixToPostfix.java at master · biblelamp/JavaExercises · GitHub

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