Create 0691-stickers-to-spell-word.kt

Author: a93a

kotlin/0691-stickers-to-spell-word.kt

@@ -0,0 +1,48 @@
+class Solution {
+    fun minStickers(stickers: Array<String>, target: String): Int {
+        val stickCount = HashMap<String, MutableMap<Char, Int>>().apply {
+            stickers.forEach { s ->
+                this[s] = s.groupingBy { it }
+                    .eachCount()
+                    .toMutableMap()
+            }
+        }
+
+        val dp = HashMap<String, Int>()
+
+        fun dfs(t: String, stick: MutableMap<Char, Int>): Int {
+            dp[t]?.let {
+                return it
+            }
+
+            var res = if (stick.isEmpty()) 0 else 1
+            val remainT = StringBuilder()
+            for (c in t) {
+                if (c in stick && stick[c]!! > 0) {
+                    stick[c] = stick[c]!! - 1
+                } else {
+                    remainT.append(c)
+                }
+            }
+
+            if (remainT.length > 0) {
+                val remainTS = remainT.toString()
+                var used = Integer.MAX_VALUE
+                for (s in stickCount.values) {
+                    if (remainTS[0]!! !in s)
+                        continue
+                    used = minOf(used, dfs(remainTS, s.toMutableMap()))
+                }
+
+                dp[remainTS] = used
+                res = if (used == Integer.MAX_VALUE ) Integer.MAX_VALUE else res + used
+            }
+
+            return res
+        }
+
+
+        val res = dfs(target, mutableMapOf<Char, Int>())
+        return if (res == Integer.MAX_VALUE) -1 else res
+    }
+}