Question

1614. Maximum Nesting Depth of the Parentheses

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Description

A string is a valid parentheses string (denoted VPS) if it meets one of the following:

• It is an empty string "", or a single character not equal to "(" or ")",
• It can be written as AB (A concatenated with B), where A and B are VPS's, or
• It can be written as (A), where A is a VPS.

We can similarly define the nesting depth depth(S) of any VPS S as follows:

• depth("") = 0
• depth(C) = 0, where C is a string with a single character not equal to "(" or ")".
• depth(A + B) = max(depth(A), depth(B)), where A and B are VPS's.
• depth("(" + A + ")") = 1 + depth(A), where A is a VPS.

For example, "", "()()", and "()(()())" are VPS's (with nesting depths 0, 1, and 2), and ")(" and "(()" are not VPS's.

Given a VPS represented as string s, return _the nesting depth of _s.

 

Example 1:

Input: s = "(1+(2*3)+((8)/4))+1"
Output: 3
Explanation: Digit 8 is inside of 3 nested parentheses in the string.

Example 2:

Input: s = "(1)+((2))+(((3)))"
Output: 3

 

Constraints:

• 1 <= s.length <= 100
• s consists of digits 0-9 and characters '+', '-', '*', '/', '(', and ')'.
• It is guaranteed that parentheses expression s is a VPS.

Solutions

Solution 1

class Solution:
  def maxDepth(self, s: str) -> int:
    ans = d = 0
    for c in s:
      if c == '(':
        d += 1
        ans = max(ans, d)
      elif c == ')':
        d -= 1
    return ans

class Solution {
  public int maxDepth(String s) {
    int ans = 0, d = 0;
    for (int i = 0; i < s.length(); ++i) {
      char c = s.charAt(i);
      if (c == '(') {
        ans = Math.max(ans, ++d);
      } else if (c == ')') {
        --d;
      }
    }
    return ans;
  }
}

class Solution {
public:
  int maxDepth(string s) {
    int ans = 0, d = 0;
    for (char& c : s) {
      if (c == '(') {
        ans = max(ans, ++d);
      } else if (c == ')') {
        --d;
      }
    }
    return ans;
  }
};

func maxDepth(s string) (ans int) {
  d := 0
  for _, c := range s {
    if c == '(' {
      d++
      ans = max(ans, d)
    } else if c == ')' {
      d--
    }
  }
  return
}

function maxDepth(s: string): number {
  let ans = 0;
  let d = 0;
  for (const c of s) {
    if (c === '(') {
      ans = Math.max(ans, ++d);
    } else if (c === ')') {
      --d;
    }
  }
  return ans;
}

/**
 * @param {string} s
 * @return {number}
 */
var maxDepth = function (s) {
  let ans = 0;
  let d = 0;
  for (const c of s) {
    if (c === '(') {
      ans = Math.max(ans, ++d);
    } else if (c === ')') {
      --d;
    }
  }
  return ans;
};

public class Solution {
  public int MaxDepth(string s) {
    int ans = 0, d = 0;
    foreach(char c in s) {
      if (c == '(') {
        ans = Math.Max(ans, ++d);
      } else if (c == ')') {
        --d;
      }
    }
    return ans;
  }
}