1614. Maximum Nesting Depth of the Parentheses

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

Python Code
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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

Java Code
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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;
    }
}

C++ Code
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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;
    }
};

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

TypeScript Code
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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;
}

JavaScript Code
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/**
 * @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;
};

C# Code
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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;
    }
}