20201106: partition array for max sum

20201106_partition_array_for_maximum_sum/main.go

@@ -0,0 +1,28 @@
+package main
+
+import (
+	"fmt"
+	"math"
+)
+
+var arr = []int{1, 40, 24, 22, 12, 4, 5, 10, 62, 9, 55, 14, 39, 89}
+
+func main() {
+	fmt.Println("solution:", findMaxSum(4, arr))
+}
+
+func findMaxSum(k int, arr []int) int {
+	l := len(arr)
+	dp := make([]int, l+1)
+	dp[0] = 0
+	for i := 0; i <= l; i++ {
+		max := -1
+
+		for j := 1; j <= k && i-j >= 0; j++ {
+			max = int(math.Max(float64(max), float64(arr[i-j])))
+			dp[i] = int(math.Max(float64(dp[i]), float64(dp[i-j]+max*j)))
+		}
+	}
+	fmt.Println(dp)
+	return dp[l]
+}

20201106_partition_array_for_maximum_sum/main_test.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"testing"
+)
+
+func Test_findMax(t *testing.T) {
+	type args struct {
+		k   int
+		arr []int
+	}
+	tests := []struct {
+		name string
+		args args
+		want int
+	}{
+		{
+			"example_1",
+			args{3, []int{1, 15, 7, 9, 2, 5, 10}},
+			84,
+		},
+		{
+			"example_2",
+			args{4, []int{1, 4, 1, 5, 7, 3, 6, 1, 9, 9, 3}},
+			83,
+		},
+		{
+			"example_3",
+			args{1, []int{1}},
+			1,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := findMaxSum(tt.args.k, tt.args.arr); got != tt.want {
+				t.Errorf("findMaxSum() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}