Improve task 2902

Author: javadev

src/main/kotlin/g2901_3000/s2902_count_of_sub_multisets_with_bounded_sum/Solution.kt

@@ -1,63 +1,66 @@
 package g2901_3000.s2902_count_of_sub_multisets_with_bounded_sum
 
 // #Hard #Array #Hash_Table #Dynamic_Programming #Sliding_Window
-// #2023_12_31_Time_249_ms_(100.00%)_Space_41.2_MB_(100.00%)
+// #2024_01_03_Time_263_ms_(87.50%)_Space_41.5_MB_(37.50%)
 
 import kotlin.math.min
 
 @Suppress("NAME_SHADOWING")
 class Solution {
+    private val mod = 1000000007
+    private val intMap = IntMap()
+
     fun countSubMultisets(nums: List<Int>, l: Int, r: Int): Int {
-        var r = r
-        INT_MAP.clear()
-        INT_MAP.add(0)
+        intMap.clear()
+        intMap.add(0)
         var total = 0
         for (num in nums) {
-            INT_MAP.add(num)
+            intMap.add(num)
             total += num
         }
         if (total < l) {
             return 0
         }
-        r = min(r, total)
+        val r = min(r, total)
         val cnt = IntArray(r + 1)
-        cnt[0] = INT_MAP.map[0]
+        cnt[0] = intMap.map[0]
         var sum = 0
-        for (i in 1 until INT_MAP.size) {
-            val `val` = INT_MAP.vals[i]
-            val count = INT_MAP.map[`val`]
+        for (i in 1 until intMap.size) {
+            val value = intMap.vals[i]
+            val count = intMap.map[value]
             if (count > 0) {
-                sum = min(r, sum + `val` * count)
-                update(cnt, `val`, count, sum)
+                sum = min(r, sum + value * count)
+                update(cnt, value, count, sum)
             }
         }
         var res = 0
         for (i in l..r) {
-            res = (res + cnt[i]) % MOD
+            res = (res + cnt[i]) % mod
         }
         return res
     }
 
     private fun update(cnt: IntArray, n: Int, count: Int, sum: Int) {
         if (count == 1) {
             for (i in sum downTo n) {
-                cnt[i] = (cnt[i] + cnt[i - n]) % MOD
+                cnt[i] = (cnt[i] + cnt[i - n]) % mod
             }
         } else {
             for (i in n..sum) {
-                cnt[i] = (cnt[i] + cnt[i - n]) % MOD
+                cnt[i] = (cnt[i] + cnt[i - n]) % mod
             }
             val max = (count + 1) * n
             for (i in sum downTo max) {
-                cnt[i] = (cnt[i] - cnt[i - max] + MOD) % MOD
+                cnt[i] = (cnt[i] - cnt[i - max] + mod) % mod
             }
         }
     }
 
     private class IntMap {
-        val map: IntArray = IntArray(MAX)
-        val vals: IntArray = IntArray(MAX)
-        var size: Int = 0
+        private val max = 20001
+        val map = IntArray(max)
+        val vals = IntArray(max)
+        var size = 0
 
         fun add(v: Int) {
             if (map[v]++ == 0) {
@@ -72,10 +75,4 @@ class Solution {
             size = 0
         }
     }
-
-    companion object {
-        private const val MOD = 1000000007
-        private const val MAX = 20001
-        private val INT_MAP = IntMap()
-    }
 }