A sentence consists of lowercase letters ('a' to 'z'), digits ('0' to '9'), hyphens ('-'), punctuation marks ('!', '.', and ','), and spaces (' ') only. Each sentence can be broken down into one or more tokens separated by one or more spaces ' '.
A token is a valid word if all three of the following are true:
Examples of valid words include "a-b.", "afad", "ba-c", "a!", and "!".
Given a string sentence, return the number of valid words in sentence.
Examples
Example 1
Input: sentence = "cat and dog"
Output: 3
Explanation: The valid words in the sentence are "cat", "and", and "dog".
Example 2
Input: sentence = "!this 1-s b8d!"
Output: 0
Explanation: There are no valid words in the sentence.
"!this" is invalid because it starts with a punctuation mark.
"1-s" and "b8d" are invalid because they contain digits.
Example 3
Input: sentence = "alice and bob are playing stone-game10"
Output: 5
Explanation: The valid words in the sentence are "alice", "and", "bob", "are", and "playing".
"stone-game10" is invalid because it contains digits.
Constraints
1 <= sentence.length <= 1000
sentence only contains lowercase English letters, digits, ' ', '-', '!', '.', and ','.
There will be at least 1 token.
2047. Number of Valid Words in a Sentence
Easy
10 Points
String
A sentence consists of lowercase letters ('a' to 'z'), digits ('0' to '9'), hyphens ('-'), punctuation marks ('!', '.', and ','), and spaces (' ') only. Each sentence can be broken down into one or more tokens separated by one or more spaces ' '.
A token is a valid word if all three of the following are true:
Examples of valid words include "a-b.", "afad", "ba-c", "a!", and "!".
Given a string sentence, return the number of valid words in sentence.
Examples
Example 1
Input: sentence = "cat and dog"
Output: 3
Explanation: The valid words in the sentence are "cat", "and", and "dog".
Example 2
Input: sentence = "!this 1-s b8d!"
Output: 0
Explanation: There are no valid words in the sentence.
"!this" is invalid because it starts with a punctuation mark.
"1-s" and "b8d" are invalid because they contain digits.
Example 3
Input: sentence = "alice and bob are playing stone-game10"
Output: 5
Explanation: The valid words in the sentence are "alice", "and", "bob", "are", and "playing".
"stone-game10" is invalid because it contains digits.
Constraints
1 <= sentence.length <= 1000
sentence only contains lowercase English letters, digits, ' ', '-', '!', '.', and ','.
There will be at least 1 token.
Number of Valid Words in a Sentence - Practice Coding | SlaveCode