package q1458

import "math"

func maxDotProduct(nums1 []int, nums2 []int) int {
	board := make([][]int, len(nums1))
	boardBuf := make([]int, len(nums1)*len(nums2))
	for i := range board {
		board[i] = boardBuf[i*len(nums2) : (i+1)*len(nums2)]
	}
	maxSingle := math.MinInt

	for i1 := range nums1 {
		for i2 := range nums2 {
			prod := nums1[i1] * nums2[i2]
			maxSingle = max(maxSingle, prod)

			if i1 > 0 && i2 > 0 {
				prod += board[i1-1][i2-1]
			}
			board[i1][i2] = max(0, prod)

			if i2 > 0 {
				board[i1][i2] = max(board[i1][i2-1], board[i1][i2])
			}
			if i1 > 0 {
				board[i1][i2] = max(board[i1-1][i2], board[i1][i2])
			}
		}
	}

	if maxSingle <= 0 {
		return maxSingle
	}
	return board[len(nums1)-1][len(nums2)-1]
}

var _ = maxDotProduct