Warm-up stack · strings

Bracket check

Your editor turns a file red when one bracket never closes. Be that check.

Write isBalanced(s): return true if every bracket in the string is closed by the matching kind, in the right order, and false otherwise. The brackets are (), [] and {}. Any other character is ignored.

Call show(line) after each bracket with the current stack as a string, for example "stack: ( [", and the stage prints the stack growing and shrinking.

Example: isBalanced("{[()]}") returns true, and isBalanced("([)]") returns false.

Tests you can see

isBalanced("()[]{}")true
isBalanced("(]")false
isBalanced("{[()]}")true

More tests are hidden. The server runs them all before a time counts.

Call show() while your code works and the run plays back here.

javascriptisBalanced()

function isBalanced(s) {
  const stack = [];
  // push openers, pop on closers, show("stack: " + stack.join(" "))
  return false;
}

function isBalanced(s) {
  const stack = [];
  // push openers, pop on closers, show("stack: " + stack.join(" "))
  return false;
}

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