"Maximum Fruits Harvested After at Most K Steps" not yet accepted, wrong answer

2106-max-fruits-harvested-in-k-steps.go

@@ -0,0 +1,114 @@
+package main
+
+func MaxTotalFruits(fruits [][]int, startPos int, k int) int {
+	if len(fruits) == 0 || k < 0 {
+		return 0
+	}
+
+	totalLength := fruits[len(fruits)-1][0] + 1
+	//fmt.Println("totalLength = ", totalLength)
+
+	if startPos >= totalLength {
+		totalLength = startPos + 1
+	}
+
+	fruitySlice := make([]int, totalLength)
+	fruityPrefix := make([]int, totalLength)
+
+	for _, fruit := range fruits {
+		fruitySlice[fruit[0]] = fruit[1]
+	}
+	//fmt.Println("fruitySlice = ", fruitySlice)
+
+	if k == 0 {
+		return fruitySlice[startPos]
+	}
+
+	prefixSum := 0
+	for i, fruit := range fruitySlice {
+		prefixSum += fruit
+		fruityPrefix[i] = prefixSum
+	}
+	//fmt.Println("fruityPrefix = ", fruityPrefix)
+
+	leftLimit := startPos - k
+	if leftLimit < 0 {
+		leftLimit = 0
+	}
+	//fmt.Println("leftLimit = ", leftLimit)
+
+	rightLimit := startPos + k
+	if rightLimit >= totalLength {
+		rightLimit = totalLength - 1
+	}
+	//fmt.Println("rightLimit = ", rightLimit)
+
+	windowSize := k / 2
+
+	calcFruitySliceSum := func(begin int, end int) int {
+		begin--
+		if begin < 0 {
+			return fruityPrefix[end]
+		}
+
+		return fruityPrefix[end] - fruityPrefix[begin]
+	}
+
+	maxFruits := calcFruitySliceSum(startPos, rightLimit)
+
+	windowBegin := startPos - (k - windowSize*2)               // in case number of steps cannot be fully divided by 2, start position is shifted 1 position to the left
+	windowEnd := windowBegin + windowSize + (k - windowSize*2) // for odd numbers of k we need to adjust wnd sz +1
+
+	if windowEnd >= rightLimit {
+		windowEnd = rightLimit
+	}
+
+	endCycle := false
+	for !endCycle {
+		if windowBegin <= leftLimit {
+			windowBegin = leftLimit
+			endCycle = true
+		}
+
+		localMaxFruits := calcFruitySliceSum(windowBegin, windowEnd)
+		if localMaxFruits > maxFruits {
+			maxFruits = localMaxFruits
+		}
+
+		windowSize++
+		windowEnd--
+		windowBegin = windowEnd - windowSize
+	}
+
+	alternativeMaxFruits := calcFruitySliceSum(leftLimit, startPos)
+	if alternativeMaxFruits > maxFruits {
+		maxFruits = alternativeMaxFruits
+	}
+
+	windowSize = k / 2
+	windowEnd = startPos + (k - windowSize*2)
+	windowBegin = windowEnd - windowSize - (k - windowSize*2)
+
+	if windowBegin <= leftLimit {
+		windowBegin = leftLimit
+	}
+
+	endCycle = false
+	for !endCycle {
+		if windowEnd >= rightLimit {
+			windowEnd = rightLimit
+			endCycle = true
+		}
+
+		localMaxFruits := calcFruitySliceSum(windowBegin, windowEnd)
+		if localMaxFruits > maxFruits {
+			maxFruits = localMaxFruits
+		}
+
+		windowSize++
+		windowBegin++
+		windowEnd = windowBegin + windowSize
+	}
+
+	return maxFruits
+}

2106-max-fruits-harvested-in-k-steps_test.go

@@ -0,0 +1,16 @@
+package main
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestMaxTotalFruits(t *testing.T) {
+
+	/*assert.Equal(t, 9, MaxTotalFruits([][]int{{2, 8}, {6, 3}, {8, 6}}, 5, 4))
+	assert.Equal(t, 14, MaxTotalFruits([][]int{{0, 9}, {4, 1}, {5, 7}, {6, 2}, {7, 4}, {10, 9}}, 5, 4))
+	assert.Equal(t, 0, MaxTotalFruits([][]int{{0, 3}, {6, 4}, {8, 5}}, 3, 2))
+	assert.Equal(t, 10000, MaxTotalFruits([][]int{{0, 10000}}, 200000, 200000))
+	assert.Equal(t, 10000, MaxTotalFruits([][]int{{200000, 10000}}, 0, 200000))*/
+	assert.Equal(t, 22, MaxTotalFruits([][]int{{1, 9}, {2, 10}, {3, 1}, {5, 6}, {6, 3}, {8, 2}, {9, 2}, {11, 4}, {18, 10}, {22, 8}, {25, 2}, {26, 2}, {30, 4}, {31, 5}, {33, 9}, {34, 1}, {39, 10}}, 19, 9))
+}