刷题--二分法（4）

public class Solution {
    /**
     * @param L: Given n pieces of wood with length L[i]
     * @param k: An integer
     * @return: The maximum length of the small pieces
     */
    public int woodCut(int[] L, int k) {
        int left = 1, right = findLongest(L);
        
        while(left + 1 < right){
            int mid = (left + right) >>> 1;
            if(numOfPices(L, mid) < k)
                right = mid;
            else
                left = mid;
        }
        
        if(numOfPices(L, right) >= k)
            return right;
        if(numOfPices(L, left) >= k)
            return left;
        return 0;
    }
    
    public int numOfPices(int[] L, int len){
        int num = 0;
        
        for(int i = 0;i < L.length;i++){
            num += L[i]/len;
        }
        
        return num;
    }
    
    public int findLongest(int[] L){
        int max = 0;
        for(int i = 0; i < L.length;i++){
            if(L[i] > max) 
                max = L[i]; 
        }
        
        return max;
    }
}