Package g1901_2000.s1963_minimum_number_of_swaps_to_make_the_string_balanced

Class Solution

  • public class Solution
extends Object
    1963 - Minimum Number of Swaps to Make the String Balanced.

    Medium

    You are given a 0-indexed string s of even length n. The string consists of exactly n / 2 opening brackets '[' and n / 2 closing brackets ']'.

    A string is called balanced if and only if:

    • It is the empty string, or
    • It can be written as AB, where both A and B are balanced strings, or
    • It can be written as [C], where C is a balanced string.

    You may swap the brackets at any two indices any number of times.

    Return the minimum number of swaps to make s balanced.

    Example 1:

    Input: s = “][][”

    Output: 1

    Explanation: You can make the string balanced by swapping index 0 with index 3. The resulting string is “[ []]”.

    Example 2:

    Input: s = “]]][[[”

    Output: 2

    Explanation: You can do the following to make the string balanced:

    • Swap index 0 with index 4. s = “[]][][”.

    • Swap index 1 with index 5. s = “[ [][]]”. The resulting string is “[ [][]]”.

    Example 3:

    Input: s = “[]”

    Output: 0

    Explanation: The string is already balanced.

    Constraints:

    • n == s.length
    • 2 <= n <= 106
    • n is even.
    • s[i] is either '[' or ']'.
    • The number of opening brackets '[' equals n / 2, and the number of closing brackets ']' equals n / 2.

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • minSwaps

        public int minSwaps​(String s)