leetcode-go/leetcode/easy/441.arranging-coins.go

func arrangeCoins(n int) int {
	// (1 + x) * x <= 2 * n < (2 + x) * (1 + x)
	lv := int(math.Sqrt(float64(2 * n)))
	for target := 2 * n; target < lv*(lv+1); lv-- {
	}
	return lv
}