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package main

import (
	"fmt"
)

/* Function to find the minimum number of reversals required
 to convert the string into a balanced expression.*/
func countRev(s string) int {
	n := len(s) // Size of string

	// If string is of odd length, it is not possible to balance the parentheses
	if n%2 != 0 {
		return -1
	}

	// To store the count of opening and closing brackets
	open, close := 0, 0

	for i := 0; i < n; i++ {
		// Increment open count if opening bracket is found
		if s[i] == '(' {
			open++
		} else {
			// Else (closing bracket is found)
			if open > 0 {
				// If an opening bracket is there, a pair of balanced parentheses is formed
				open--
			} else {
				// Otherwise, the closing bracket remains unbalanced
				close++
			}
		}
	}

	// Computing the result
	ans := (open / 2) + (open % 2) + (close / 2) + (close % 2)

	return ans // Return the result
}

func main() {
	s := ")(())((("

	// Function call to find the minimum number of reversals
	// required to convert the string into a balanced expression.
	ans := countRev(s)

	// Output
	fmt.Println("The minimum number of reversals required are:", ans)
}

Complexity Analysis:

Time Complexity: O(n) (where n is the length of the input string)
The input string is traversed once taking O(n) time.

Space Complexity: O(1)
Only a couple of variables are used taking constant space.

1d:T473,class Solution { public: /* Function to find the minimum number of reversals required to convert the string into a balanced expression. */ int countRev(string s) { int n = s.length(); // Size of string /* If string is of odd length, it is not possible to balance the paranthesis */ if(n % 2) return -1; // To store the count of opening and closing brackets int open = 0, close = 0; for(int i=0; i < n; i++) { // Increment open count if opening bracket is found if(s[i] == '(') open++; // Else (closing bracket is found) else { /* If a opening bracket is there, a pair of balanced paranthesis is formed */ if(open > 0) open--; // Otherwise the closing bracket remain unbalanced else close++; } } // Computing the result int ans = (open / 2) + (open % 2) + (close / 2) + (close % 2); return ans; // Return the result } };1e:T4f6,public class Solution { /* Function to find the minimum number of reversals required to convert the string into a balanced expression. */ public int countRev(string s) { int n = s.Length; // Size of string /* If string is of odd length, it is not possible to balance the paranthesis */ if (n % 2 != 0) return -1; // To store the count of opening and closing brackets int open = 0, close = 0; for (int i = 0; i < n; i++) { // Increment open count if opening bracket is found if (s[i] == '(') open++; // Else (closing bracket is found) else { /* If a opening bracket is there, a pair of balanced paranthesis is formed */