Wood Cut

Given n pieces of wood with length L[i] (integer array). Cut them into small pieces to guarantee you could have equal or more than k pieces with the same length. What is the longest length you can get from the n pieces of wood? Given L & k, return the maximum length of the small pieces.

Notice

You couldn't cut wood into float length.

Example For L=[232, 124, 456], k=7, return 114.

Solution: Binary search length from 1 to max length. If the total number of that kind of length equals to k,then we find the result.

public int woodCut(int[] L, int k) {
    if (L == null || L.length == 0)
        return 0;
    int max = Integer.MIN_VALUE;
    for (int i = 0; i < L.length; i++) {
        max = Math.max(max, L[i]);
    }
    int start = 1, end = max;
    while(start <= end) {
        int mid = start + (end - start) / 2;
        if(findK(mid, L) >= k) {
            start = mid + 1;
        }
        else {
            end = mid - 1;
        }
    }

    return end;
}

public int findK(int n, int[] L) {
    int sum = 0;
    for(int i = 0; i < L.length; i++) {
        sum += L[i] / n;   
    }
    return sum;
}