20200614SolutionCuttingPiles.java

class Solution{
    public cutPiles(int[] piles, int target){
        int max = 0;
        for(int pile : piles){
            max = Math.max(max, pile);
        }
        
        int lo = 1, hi = max;
        
        while(lo < hi){
            int mid = lo + (hi - lo) / 2;
            
            int cuts = getCounts(piles, mid);
            
            if(target < cuts) hi = mid;
            else lo = mid + 1;
        }
        
        return hi - 1;
    }
    
    private int getCounts(int[] piles, int cut){
        int cuts = 0;
        for(int pile : piles) 
            if(pile >= cut)
                cuts += pile / cut;
        return cuts;
    }
}