Print Bracket Number

 Given a string str, the task is to find the bracket numbers, i.e., for each bracket in str, return i if the bracket is the ith opening or closing bracket to appear in the string. 


 Examples:


Input:  str = "(aa(bdc))p(dee)"

Output: 1 2 2 1 3 3

Explanation: The highlighted brackets in

the given string (aa(bdc))p(dee) are

assigned the numbers as: 1 2 2 1 3 3.

Input:  str = "(((()("

Output: 1 2 3 4 4 5

Explanation: The highlighted brackets in

the given string (((()( are assigned

the numbers as: 1 2 3 4 4 5

Expected Time Complexity: O(|str|)

Expected Auxiliary Space: O(|str|)



import java.util.*;

public class BracketNumbersStack {
    public static void main(String[] args) {
        String str = "(aa(bdc))p(dee)";
        List<Integer> result = getBracketNumbers(str);
        for (int num : result) {
            System.out.print(num + " ");
        }
    }

    public static List<Integer> getBracketNumbers(String str) {
        Stack<Integer> stack = new Stack<>();
        List<Integer> output = new ArrayList<>();
        int count = 0; // to assign numbers to opening brackets

        for (char c : str.toCharArray()) {
            if (c == '(') {
                count++;
                stack.push(count);
                output.add(count);  // opening bracket gets new number
            } else if (c == ')') {
                int openNum = stack.pop(); // closing bracket matches opening
                output.add(openNum);
            }
            // ignore other chars
        }
        return output;
    }
}

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