Class Solution


  • public class Solution
    extends Object
    65 - Valid Number.

    Hard

    A valid number can be split up into these components (in order):

    1. A decimal number or an integer.
    2. (Optional) An 'e' or 'E', followed by an integer.

    A decimal number can be split up into these components (in order):

    1. (Optional) A sign character (either '+' or '-').
    2. One of the following formats:
      1. One or more digits, followed by a dot '.'.
      2. One or more digits, followed by a dot '.', followed by one or more digits.
      3. A dot '.', followed by one or more digits.

    An integer can be split up into these components (in order):

    1. (Optional) A sign character (either '+' or '-').
    2. One or more digits.

    For example, all the following are valid numbers: ["2", "0089", "-0.1", "+3.14", "4.", "-.9", "2e10", "-90E3", "3e+7", "+6e-1", "53.5e93", "-123.456e789"], while the following are not valid numbers: ["abc", "1a", "1e", "e3", "99e2.5", "--6", "-+3", "95a54e53"].

    Given a string s, return true if s is a valid number.

    Example 1:

    Input: s = “0”

    Output: true

    Example 2:

    Input: s = “e”

    Output: false

    Example 3:

    Input: s = “.”

    Output: false

    Example 4:

    Input: s = “.1”

    Output: true

    Constraints:

    • 1 <= s.length <= 20
    • s consists of only English letters (both uppercase and lowercase), digits (0-9), plus '+', minus '-', or dot '.'.
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • isNumber

        public boolean isNumber​(String s)