Given a string of brackets, the task is to find an index k which decides the number of opening brackets is equal to the number of closing brackets.
String must be consists of only opening and closing brackets i.e. ‘(‘ and ‘)’.
An equal point is an index such that the number of opening brackets before it is equal to the number of closing brackets from and after.
Input : str = "(())))(" Output: 4 After index 4, string splits into (()) and ))(. Number of opening brackets in the first part is equal to number of closing brackets in the second part. Input : str = "))" Output: 2 As after 2nd position i.e. )) and "empty" string will be split into these two parts: So, in this number of opening brackets i.e. 0 in the first part is equal to number of closing brackets in the second part i.e. also 0.
Asked in : Amazon
- Store the number of opening brackets appears in the string up to every index, it must start from starting index.
- Similarly, Store the number of closing brackets appears in the string upto each and every index but it should be done from last index.
- Check if any index has the same value of opening and closing brackets.
Time Complexity : O(n)
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Improved By : chitranayal