Write a function int checkBalance(char exp[]); that can take an expression as input and check whether the parenthesis used in that expression are valid or invalid. It returns 1 if it is valid, and returns 0 if it is not valid. For example, the following expressions are valid: [ A * {B + (C + D)}] and [{()()}]

The following expressions are invalid:

[ A * {B + (C + D})], [ { ( ] ) ( ) }