feat: Add RodCuttingMaxProfit algorithm #42

Sources/DynamicProgramming/RodCuttingMaxProfit.swift

@@ -0,0 +1,47 @@
+//
+//  RodCuttingMaxProfit.swift
+//  SwiftyAlgorithms
+//
+//  Created by Mohshinsha Shahmadar on 2025-04-23.
+//
+
+import Foundation
+
+/**
+ Given a rod of length n and an array of prices that contains prices of all pieces of size smaller than n.
+ Determine the maximum profit obtainable by cutting up the rod and selling the pieces.
+
+ Sample inputs and outputs:
+ Input: [1, 5, 8, 9, 10, 17, 17, 20]
+ Output: 22
+ */
+func rodCuttingMaxProfit(_ prices: [Int]) -> Int {
+  if prices.isEmpty {
+    return 0
+  } else if prices.count == 1 {
+    return prices[0]
+  } else {
+    let priceArray = [0] + prices
+    var bestProfit = Array.init(repeating: 0, count: priceArray.count)
+
+    bestProfit[0] = 0
+    bestProfit[1] = priceArray[1]
+
+    for rodLength in 2..<bestProfit.count {
+      var maximumProfit = priceArray[rodLength]
+
+      for potentialCut in stride(from: rodLength, through: 1, by: -1) {
+        let remainingRodLength = rodLength - potentialCut
+        let remainingRodBestPrice = bestProfit[remainingRodLength]
+        let totalProfitWithCutAndRemainingBest = remainingRodBestPrice + priceArray[potentialCut]
+
+        if totalProfitWithCutAndRemainingBest > maximumProfit {
+          maximumProfit = totalProfitWithCutAndRemainingBest
+        }
+      }
+      bestProfit[rodLength] = maximumProfit
+    }
+
+    return bestProfit[prices.count]
+  }
+}

Tests/SwiftyAlgorithmsTests/DynamicProgramming/RodCuttingMaxProfitTests.swift

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+//
+//  RodCuttingMaxProfitTests.swift
+//  SwiftyAlgorithms
+//
+//  Created by Mohshinsha Shahmadar on 2025-04-24.
+//
+
+import XCTest
+@testable import SwiftyAlgorithms
+
+final class RodCuttingMaxProfitTests: XCTestCase {
+  func testRodCuttingMaxProfit() throws {
+    let inputs: [AlgorithmTestCase] = [
+      .init([], 0),
+      .init([5], 5),
+      .init([1, 5, 8, 9, 10, 17, 17, 20], 22)
+    ]
+
+    testAlgorithm(name: "RodCutting - MaxProfit", with: inputs) {
+      rodCuttingMaxProfit($0)
+    }
+  }
+}