LeetCode in Kotlin
859. Buddy Strings
Easy
Given two strings s and goal, return true if you can swap two letters in s so the result is equal to goal, otherwise, return false.
Swapping letters is defined as taking two indices i and j (0-indexed) such that i != j and swapping the characters at s[i] and s[j].
- For example, swapping at indices
0and2in"abcd"results in"cbad".
Example 1:
Input: s = “ab”, goal = “ba”
Output: true
Explanation: You can swap s[0] = ‘a’ and s[1] = ‘b’ to get “ba”, which is equal to goal.
Example 2:
Input: s = “ab”, goal = “ab”
Output: false
Explanation: The only letters you can swap are s[0] = ‘a’ and s[1] = ‘b’, which results in “ba” != goal.
Example 3:
Input: s = “aa”, goal = “aa”
Output: true
Explanation: You can swap s[0] = ‘a’ and s[1] = ‘a’ to get “aa”, which is equal to goal.
Constraints:
1 <= s.length, goal.length <= 2 * 104sandgoalconsist of lowercase letters.
Solution
class Solution {
fun buddyStrings(s: String, goal: String): Boolean {
var first = -1
val second: Int
val sCounts = IntArray(26)
if (s == goal) {
for (i in s.indices) {
sCounts[s[i].code - 'a'.code]++
if (sCounts[s[i].code - 'a'.code] > 1) {
return true
}
}
}
for (i in s.indices) {
val curr = s[i]
sCounts[curr.code - 'a'.code]++
if (curr != goal[i]) {
if (first == -1) {
first = i
} else {
second = i
val ss = s.toCharArray()
val temp = ss[first]
ss[first] = ss[second]
ss[second] = temp
return String(ss) == goal
}
}
}
return false
}
}