数字的寻找的问题，具体的C语言实现

Problem Description
Give you three sequences of numbers A, B, C, then we give you a number X. Now you need to calculate if you can find the three numbers Ai, Bj, Ck, which satisfy the formula Ai+Bj+Ck = X.

Input
There are many cases. Every data case is described as followed: In the first line there are three integers L, N, M, in the second line there are L integers represent the sequence A, in the third line there are N integers represent the sequences B, in the forth line there are M integers represent the sequence C. In the fifth line there is an integer S represents there are S integers X to be calculated. 1<=L, N, M<=500, 1<=S<=1000. all the integers are 32-integers.

Output
For each case, firstly you have to print the case number as the form "Case d:", then for the S queries, you calculate if the formula can be satisfied or not. If satisfied, you print "YES", otherwise print "NO".

Sample Input
3 3 3
1 2 3
1 2 3
1 2 3
3
1
4
10

Sample Output
Case 1:
NO
YES
NO

太晚了，不给你码了。。。
核心思想：三层for循环应该不超时，每次判断a[i], b[j], c[k] 的和即可

for (int i = 0; i < l; i++)
    for (int j = 0; j < m; j++)
        for (int k = 0; k < n; k++)
            if ((a[i] + b[j] + c[k]) == X

优化一下的话可以先排序，从小到大三个队列排序。如果某个i j k的和超过X，直接就 NO 了。

后来看了下，好像三层循环会超时，按我的优化方法是一下，明天我看看有没有更好的思路