Koko Eating Bananas

def minEatingSpeed(piles, h):
    l, r = 1, max(piles)
    res = r
    
    while l <= r:
        k = (l + r) // 2
        
        totalTime = 0
        for p in piles:
            totalTime += math.ceil(float(p) / k)
            
        if totalTime <= h:
            res = min(res, k)
            r = k - 1
        else:
            l = k + 1
            
    return res