### Balanced Brackets and Parentheses.

Difficulty (2/5).Many languages enclose expressions using brackets or parentheses of various kinds. For example, in Java, you might see expressions like the following:

s = new ArrayList<>(); A[(i*2)+1] = ((x+2)*(y-2)); public int getValue() { return val; }Notice how in all of these cases there is a "balancing principle" that gives the brackets a hierarchical structure. The rules for this balancing are as follows:

- Each open bracket must have a corresponding close bracket of the same kind to the right. Thus getValue() is balanced, but getValue(} is not.
- A closing bracket must be the same kind as the nearest unclosed open bracket to the left. Thus, A[(i*2)+1] is balanced, but A[(i*2]) is not.

(), [], {}, <>Test your program on the following expressions:

BALANCED: (a+3)*(b+2) {a[1], b[2], c[3]} void alloc() { x = new ArrayList<>(b[3]); } <<<< ((( [[ { x } ]] ))) >>>> NOT BALANCED: A[1) = 34; (((( b ))) :) (:Hint: Use a stack data structure.

CS1 Deadline: 12/6/2013

Use: handin cs1113 extra6 BalancedBrackets.java

Dr. Cline the following expression would count as balanced or unbalanced?

ReplyDelete"<(expression>)" ?? There is a balanced number of each closing brackets type but not in the same order. Is it considered balanced or unbalanced?

That's considered unbalanced. Also )( is considered unbalanced, whereas () is balanced.

ReplyDelete