Check for Balance

Write a function that takes a string of source code and checks whether the braces/parentheses are balanced. Every ( or { must be closed by a } or ) in the opposite order. Return the index at which an imbalance occurs, or -1 if the string is balanced. If any ( or { are never closed, return the string's length.

Examples

check_balance("if (a(4) > 9) { foo(a(2)); }") ➞ -1
# Returns -1 because it's balanced.

check_balance("for (i=0;i<a(3};i++) { foo{); )") ➞ 14
# Returns 14 because } is out of order.

check_balance("if (x) {")  ➞ 8
# Returns 8 because { is never closed.

Notes

Think about how you can leverage Stack Data Structure.