carloscn
commented
1 year ago Analysis
pub fn largest_good_integer(num: &str) -> String
{
let mut ret:String = String::new();
if num.is_empty() {
return ret;
}
let mut max_val:u8 = u8::MIN;
let num_vec:Vec<char> = num.chars().collect();
for i in 0..num_vec.len() - 2 {
if (num_vec[i] == num_vec[i + 1]) &&
(num_vec[i] == num_vec[i + 2]) {
max_val = (num_vec[i] as u8).max(max_val);
}
}
if max_val != u8::MIN {
for _i in 0..3 {
ret.push(max_val as char);
}
}
return ret;
}
Description
You are given a string num representing a large integer. An integer is good if it meets the following conditions:
It is a substring of num with length 3. It consists of only one unique digit. Return the maximum good integer as a string or an empty string "" if no such integer exists.
Note:
A substring is a contiguous sequence of characters within a string. There may be leading zeroes in num or a good integer.
Example 1:
Input: num = "6777133339" Output: "777" Explanation: There are two distinct good integers: "777" and "333". "777" is the largest, so we return "777".
Example 2:
Input: num = "2300019" Output: "000" Explanation: "000" is the only good integer.
Example 3:
Input: num = "42352338" Output: "" Explanation: No substring of length 3 consists of only one unique digit. Therefore, there are no good integers.
Constraints:
3 <= num.length <= 1000 num only consists of digits.