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refactor: InfixToPostfix (#5401)

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This commit is contained in:
Alex Klymenko
2024-08-26 15:43:13 +02:00
committed by GitHub
parent 64ff9b2efe
commit 4347f5b9f6
2 changed files with 42 additions and 7 deletions
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16
src/main/java/com/thealgorithms/stacks/InfixToPostfix.java
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@ -1,19 +1,15 @@
package com.thealgorithms.stacks;
import java.util.Stack;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public final class InfixToPostfix {
private InfixToPostfix() {
}
public static void main(String[] args) throws Exception {
assert "32+".equals(infix2PostFix("3+2"));
assert "123++".equals(infix2PostFix("1+(2+3)"));
assert "34+5*6-".equals(infix2PostFix("(3+4)*5-6"));
}
public static String infix2PostFix(String infixExpression) throws Exception {
if (!BalancedBrackets.isBalanced(infixExpression)) {
if (!BalancedBrackets.isBalanced(filterBrackets(infixExpression))) {
throw new Exception("invalid expression");
}
StringBuilder output = new StringBuilder();
@ -55,4 +51,10 @@ public final class InfixToPostfix {
return -1;
}
}
private static String filterBrackets(String input) {
Pattern pattern = Pattern.compile("[^(){}\\[\\]<>]");
Matcher matcher = pattern.matcher(input);
return matcher.replaceAll("");
}
}