LeetCode in Kotlin
3121. Count the Number of Special Characters II
Medium
You are given a string word. A letter c is called special if it appears both in lowercase and uppercase in word, and every lowercase occurrence of c appears before the first uppercase occurrence of c.
Return the number of special letters in word.
Example 1:
Input: word = “aaAbcBC”
Output: 3
Explanation:
The special characters are 'a', 'b', and 'c'.
Example 2:
Input: word = “abc”
Output: 0
Explanation:
There are no special characters in word.
Example 3:
Input: word = “AbBCab”
Output: 0
Explanation:
There are no special characters in word.
Constraints:
1 <= word.length <= 2 * 105wordconsists of only lowercase and uppercase English letters.
Solution
import kotlin.math.min
class Solution {
fun numberOfSpecialChars(word: String): Int {
val small = IntArray(26)
small.fill(-1)
val capital = IntArray(26)
capital.fill(Int.MAX_VALUE)
var result = 0
for (i in word.indices) {
val a = word[i]
if (a.code < 91) {
capital[a.code - 65] = min(capital[a.code - 65].toDouble(), i.toDouble()).toInt()
} else {
small[a.code - 97] = i
}
}
for (i in 0..25) {
if (-1 != small[i] && Int.MAX_VALUE != capital[i] && capital[i] > small[i]) {
result++
}
}
return result
}
}