2042. Check if Numbers Are Ascending in a Sentence

Problem

A sentence is a list of tokens separated by a single space with no leading or trailing spaces. Every token is either a positive number consisting of digits 0-9 with no leading zeros, or a word consisting of lowercase English letters.

• For example, "a puppy has 2 eyes 4 legs" is a sentence with seven tokens: "2" and "4" are numbers and the other tokens such as "puppy" are words.

Given a string s representing a sentence, you need to check if all the numbers in s are strictly increasing from left to right (i.e., other than the last number, each number is strictly smaller than the number on its right in s).

Return true** if so, or false otherwise**.

  Example 1:

Input: s = "1 box has 3 blue 4 red 6 green and 12 yellow marbles"
Output: true
Explanation: The numbers in s are: 1, 3, 4, 6, 12.
They are strictly increasing from left to right: 1 < 3 < 4 < 6 < 12.

Example 2:

Input: s = "hello world 5 x 5"
Output: false
Explanation: The numbers in s are: 5, 5. They are not strictly increasing.

Example 3:

Input: s = "sunset is at 7 51 pm overnight lows will be in the low 50 and 60 s"
Output: false
Explanation: The numbers in s are: 7, 51, 50, 60. They are not strictly increasing.

  Constraints:

• 3 <= s.length <= 200

• s consists of lowercase English letters, spaces, and digits from 0 to 9, inclusive.

• The number of tokens in s is between 2 and 100, inclusive.

• The tokens in s are separated by a single space.

• There are at least two numbers in s.

• Each number in s is a positive number less than 100, with no leading zeros.

• s contains no leading or trailing spaces.

Solution (Java)

class Solution {
    public boolean areNumbersAscending(String s) {
        String[] words = s.split("\\ ");
        int prev = 0;
        for (String word : words) {
            if (Character.isDigit(word.charAt(0))) {
                if (Integer.parseInt(word) <= prev) {
                    return false;
                } else {
                    prev = Integer.parseInt(word);
                }
            }
        }
        return true;
    }
}

Explain:

nope.

Complexity:

• Time complexity : O(n).
• Space complexity : O(n).