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Practice Valid Number

Read the task, work through the examples, and check your approach against the constraints. Use the original LeetCode task for coding and submissions.

Hard#65
LeetCode Problem

Valid Number

String

Problem Statement

Return whether s is a valid numeric string. It may begin with + or -. Its main part must be either one or more digits, digits followed by a decimal point with optional following digits, or a decimal point followed by one or more digits. An optional exponent starts with e or E and then contains an optional sign followed by one or more digits. The exponent cannot contain a decimal point. No other characters or extra signs are allowed. Thus 4., -.9 and 3e+7 are valid, while 1e and 99e2.5 are not.

Source: Valid Number on LeetCode. Use the original task for its coding environment and submissions.

Examples

# Example 1

Input
s = "0"
Output
true

# Example 2

Input
s = "e"
Output
false

# Example 3

Input
s = "."
Output
false

Constraints

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

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