How to check if a String is balanced?

java, stack, string

Solution

1) For every opening bracket: `{ [ (` push it to the stack.

2) For every closing bracket: `} ] )` pop from the stack and check whether the type of bracket matches. If not return `false`;

i.e. current symbol in String is `}` and if poped from stack is anything else from `{` then return `false` immediately.

3) If end of line and stack is not empty, return `false`, otherwise `true`.

Problem

I want to test if an input String is balanced. It would be balanced if there is a matching opening and closing parenthesis, bracket or brace. ``` example: {} balanced () balanced [] balanced If S is balanced so is (S) If S and T are balanced so is ST public static boolean isBalanced(String in) { Stack st = new Stack(); for(char chr : in.toCharArray()) { if(chr == '{') st.push(chr); } return false; } ``` I'm having problems choosing what to do. Should I put every opening or closing parenthesis, bracket, or brace in a stack then pop them out? If I pop them out, how does that really help me?

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