LeetCode in Kotlin
2264. Largest 3-Same-Digit Number in String
Easy
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
numwith length3. - 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
numor 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 <= 1000numonly consists of digits.
Solution
class Solution {
fun largestGoodInteger(num: String): String {
var maxi = "000"
var c = 0
for (i in 0 until num.length - 2) {
val s = num.substring(i, i + 3)
if (s[0] == s[1] && s[1] == s[2]) {
if (s.compareTo(maxi) >= 0) {
maxi = s
}
++c
}
}
return if (c == 0) {
""
} else maxi
}
}