## Go, dynamic_programming, rodcutting.go

``````// Solution to Rod cutting problem
// https://en.wikipedia.org/wiki/Cutting_stock_problem
// http://www.geeksforgeeks.org/dynamic-programming-set-13-cutting-a-rod/

package dynamic

// CutRodRec solve the problem recursively: initial approach
func CutRodRec(price []int, length int) int {
if length == 0 {
return 0
}

q := -1
for i := 1; i <= length; i++ {
q = Max(q, price[i]+CutRodRec(price, length-i))
}
return q
}

// CutRodDp solve the same problem using dynamic programming
func CutRodDp(price []int, length int) int {
r := make([]int, length+1) // a.k.a the memoization array
r[0] = 0                   // cost of 0 length rod is 0

for j := 1; j <= length; j++ { // for each length (subproblem)
q := -1
for i := 1; i <= j; i++ {
q = Max(q, price[i]+r[j-i]) // avoiding recursive call
}
r[j] = q
}

return r[length]
}

/*
func main() {
length := 10
price := []int{0, 1, 5, 8, 9, 17, 17, 17, 20, 24, 30}
// price := []int{0, 10, 5, 8, 9, 17, 17, 17, 20, 24, 30}

// fmt.Print(price[5]+price[length-5], "\n")

fmt.Print(cutRodRec(price, length), "\n")
fmt.Print(cutRodDp(price, length), "\n")
}
*/
``````