LeetCode/go/make-sum-divisible-by-p.go

package main

func minSubarray(nums []int, p int) int {
	getTotalRemainder := func() int {
		total := 0
		for _, x := range nums {
			total = (total + x) % p
		}
		return total
	}
	target := getTotalRemainder()

	// whole array is divisible by p
	if target == 0 {
		return 0
	}

	mods := make(map[int]int)
	mods[0] = -1

	runningRemainder, foundMinimum := 0, len(nums)
	for i, x := range nums {
		runningRemainder = (runningRemainder + x) % p

		complement := (runningRemainder + p - target) % p
		length, found := mods[complement]
		if found {
			foundMinimum = min(foundMinimum, i-length)
		}

		mods[runningRemainder] = i
	}

	// didn't find any solution
	if foundMinimum == len(nums) {
		return -1
	}

	return foundMinimum
}