LeetCode/kt/word-break-ii.kt
Matej Focko 8157017f38
kt: add «140. Word Break II»
Signed-off-by: Matej Focko <me@mfocko.xyz>
2024-05-26 00:41:14 +02:00

59 lines
1.6 KiB
Kotlin

class Solution {
private fun precomputeFrom(
words: List<String>,
s: String,
dp: Map<Int, List<String>>,
start: Int,
): List<String> {
val valid = mutableListOf<String>()
(start..<s.length)
.map { end -> end to s.substring(start..end) }
.filter { (_, word) -> words.contains(word) }
.forEach { (end, word) ->
when {
end == s.length - 1 -> valid.add(word)
else -> {
dp[end + 1]?.forEach { suffix ->
valid.add("$word $suffix")
}
}
}
}
return valid
}
fun wordBreak(
s: String,
wordDict: List<String>,
): List<String> {
val dp = mutableMapOf<Int, List<String>>()
s.indices.reversed().forEach { start ->
dp[start] = precomputeFrom(wordDict, s, dp, start)
}
return dp.getOrDefault(0, emptyList())
}
}
fun main() {
val s = Solution()
check(
s.wordBreak("catsanddog", listOf("cat", "cats", "and", "sand", "dog")).sorted() ==
listOf(
"cats and dog", "cat sand dog",
).sorted(),
)
check(
s.wordBreak("pineapplepenapple", listOf("apple", "pen", "applepen", "pine", "pineapple")).sorted() ==
listOf(
"pine apple pen apple", "pineapple pen apple", "pine applepen apple",
).sorted(),
)
check(
s.wordBreak("catsandog", listOf("cats", "dog", "sand", "and", "cat")) == emptyList<String>(),
)
}