Improved tasks 194, 1022, 2366, 3473

Author: javadev

src/main/kotlin/g0101_0200/s0194_transpose_file/script.sh

@@ -1,8 +1,17 @@
 # Read from the file file.txt and print its transposed content to stdout.
-# #Medium #Shell #2022_11_25_Time_461_ms_(33.47%)_Space_3.9_MB_(34.89%)
-wordcount=$(head -1 file.txt | wc -w)
-col_n=1
-while [[ $col_n -le $wordcount ]]; do
-	awk "{ print \$$col_n }" file.txt | paste -sd " "
-	col_n=$((col_n + 1))
-done
+# #Medium #Shell #2025_05_03_Time_61_ms_(88.19%)_Space_4.14_MB_(38.67%)
+awk '
+{
+    for (i = 1; i <= NF; i++) {
+        if (NR == 1) {
+            a[i] = $i
+        } else {
+            a[i] = a[i] " " $i
+        }
+    }
+}
+END {
+    for (i = 1; i <= NF; i++) {
+        print a[i]
+    }
+}' file.txt

src/main/kotlin/g1001_1100/s1022_sum_of_root_to_leaf_binary_numbers/Solution.kt

@@ -1,7 +1,7 @@
 package g1001_1100.s1022_sum_of_root_to_leaf_binary_numbers
 
 // #Easy #Depth_First_Search #Tree #Binary_Tree
-// #2023_05_22_Time_158_ms_(88.89%)_Space_36.3_MB_(11.11%)
+// #2025_05_03_Time_0_ms_(100.00%)_Space_41.68_MB_(93.33%)
 
 import com_github_leetcode.TreeNode
 
@@ -17,31 +17,18 @@ import com_github_leetcode.TreeNode
  */
 class Solution {
     fun sumRootToLeaf(root: TreeNode?): Int {
-        val paths: MutableList<List<Int>> = ArrayList()
-        dfs(root, paths, ArrayList())
-        var sum = 0
-        for (list in paths) {
-            var num = 0
-            for (i in list) {
-                num = (num shl 1) + i
-            }
-            sum += num
-        }
-        return sum
+        return sumRootToLeaf(root, 0)
     }
 
-    private fun dfs(root: TreeNode?, paths: MutableList<List<Int>>, path: MutableList<Int>) {
-        path.add(root!!.`val`)
-        if (root.left != null) {
-            dfs(root.left!!, paths, path)
-            path.removeAt(path.size - 1)
-        }
-        if (root.right != null) {
-            dfs(root.right!!, paths, path)
-            path.removeAt(path.size - 1)
+    private fun sumRootToLeaf(root: TreeNode?, sum: Int): Int {
+        var sum = sum
+        if (root == null) {
+            return 0
         }
+        sum = 2 * sum + root.`val`
         if (root.left == null && root.right == null) {
-            paths.add(ArrayList(path))
+            return sum
         }
+        return sumRootToLeaf(root.left, sum) + sumRootToLeaf(root.right, sum)
     }
 }

src/main/kotlin/g2301_2400/s2366_minimum_replacements_to_sort_the_array/Solution.kt

@@ -1,18 +1,19 @@
 package g2301_2400.s2366_minimum_replacements_to_sort_the_array
 
-// #Hard #Array #Math #Greedy #2023_07_02_Time_433_ms_(100.00%)_Space_57.9_MB_(100.00%)
+// #Hard #Array #Math #Greedy #2025_05_03_Time_4_ms_(100.00%)_Space_60.26_MB_(66.67%)
 
 class Solution {
     fun minimumReplacement(nums: IntArray): Long {
-        var limit = nums[nums.size - 1]
+        val n = nums.size
+        var prev = nums[n - 1]
         var ans: Long = 0
-        for (i in nums.size - 2 downTo 0) {
-            var replacements = nums[i] / limit - 1
-            if (nums[i] % limit != 0) {
-                replacements++
+        for (i in n - 2 downTo 0) {
+            var noOfTime = nums[i] / prev
+            if (nums[i] % prev != 0) {
+                noOfTime++
+                prev = nums[i] / noOfTime
             }
-            ans += replacements.toLong()
-            limit = nums[i] / (replacements + 1)
+            ans += (noOfTime - 1).toLong()
         }
         return ans
     }

src/main/kotlin/g3401_3500/s3473_sum_of_k_subarrays_with_length_at_least_m/Solution.kt

@@ -1,45 +1,26 @@
 package g3401_3500.s3473_sum_of_k_subarrays_with_length_at_least_m
 
 // #Medium #Array #Dynamic_Programming #Prefix_Sum
-// #2025_03_06_Time_227_ms_(24.47%)_Space_99.61_MB_(48.94%)
-
-import kotlin.math.max
+// #2025_05_03_Time_33_ms_(98.18%)_Space_81.75_MB_(87.27%)
 
 class Solution {
     fun maxSum(nums: IntArray, k: Int, m: Int): Int {
         val n = nums.size
-        // Calculate prefix sums
-        val prefixSum = IntArray(n + 1)
-        for (i in 0..<n) {
-            prefixSum[i + 1] = prefixSum[i] + nums[i]
+        val dp = Array(k + 1) { IntArray(n + 1) { Int.MIN_VALUE } }
+        val ps = IntArray(n + 1)
+        for (i in nums.indices) {
+            ps[i + 1] = ps[i] + nums[i]
         }
-        // using elements from nums[0...i-1]
-        val dp = Array<IntArray>(n + 1) { IntArray(k + 1) }
-        // Initialize dp array
-        for (j in 1..k) {
-            for (i in 0..n) {
-                dp[i][j] = Int.Companion.MIN_VALUE / 2
-            }
+        for (j in 0..n) {
+            dp[0][j] = 0
         }
-        // Fill dp array
-        for (j in 1..k) {
-            val maxPrev = IntArray(n + 1)
-            for (i in 0..<n + 1) {
-                maxPrev[i] =
-                    if (i == 0) {
-                        dp[0][j - 1] - prefixSum[0]
-                    } else {
-                        max(maxPrev[i - 1], dp[i][j - 1] - prefixSum[i])
-                    }
-            }
-            for (i in m..n) {
-                // Option 1: Don't include the current element in any new subarray
-                dp[i][j] = dp[i - 1][j]
-                // Option 2: Form a new subarray ending at position i
-                // Find the best starting position for the subarray
-                dp[i][j] = max(dp[i][j], prefixSum[i] + maxPrev[i - m])
+        for (i in 1..k) {
+            var best = Int.MIN_VALUE
+            for (j in (i * m)..n) {
+                best = maxOf(best, dp[i - 1][j - m] - ps[j - m])
+                dp[i][j] = maxOf(dp[i][j - 1], ps[j] + best)
             }
         }
-        return dp[n][k]
+        return dp[k][n]
     }
 }

src/test/kotlin/g1001_1100/s1022_sum_of_root_to_leaf_binary_numbers/SolutionTest.kt

@@ -17,4 +17,9 @@ internal class SolutionTest {
         val root: TreeNode? = TreeNode.create(listOf(0))
         assertThat(Solution().sumRootToLeaf(root), equalTo(0))
     }
+
+    @Test
+    fun sumRootToLeaf3() {
+        assertThat(Solution().sumRootToLeaf(null), equalTo(0))
+    }
 }