If a stack is used by an algorithm to check for balanced braces,which of the following is true once the end of the string is reached?
A)the stack is empty
B)the stack has one "{"
C)the stack has one "}"
D)the stack has one "{" and one "}"

Question

Quizplus · Accepted Answer

If the algorithm is designed correctly, every time it encounters an opening brace it will push it onto the stack, and every time it encounters a closing brace it will pop the top element from the stack and compare it to the closing brace. If they match, it will continue to the next character in the string. If they do not match, it will indicate that the string is not balanced. Once the end of the string is reached, if all the braces were balanced, the stack should be empty. Therefore, the correct choice is A) the stack is empty.

If a Stack Is Used by an Algorithm to Check