Thinking process

Find the largest number that satisfy cutwood(num) >= k

O (n log max)

Mistakes

where to start? where to end?

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) {
        if (L == null || L.length == 0 || k == 0) return 0;

        int start = 1;
        int end = 1;
        for (int i = 0; i < L.length; ++i) {
            end = Math.max(L[i], end);
        }

        while (start + 1 < end) {
            int mid = (end - start) / 2 + start;

            if (cutWood(mid, L) == k) {
                start = mid;
            } else if (cutWood(mid, L) < k) {
                end = mid;
            } else {
                start = mid;
            }
        }

        if (cutWood(end, L) >= k) return end;
        if (cutWood(start, L) >= k) return start;

        return 0;
    }

    private int cutWood(int length, int[] L){
        int result = 0;

        for (int i = 0; i < L.length; ++i) {
            result += L[i] / length;
        }

        return result;
    }
}

results matching ""

    No results matching ""