求和数等于X的Sum数组值

我有一个整数集合.我需要得到值总和等于X的所有可能性.

我需要像这样.

它可以写成:delphi,c#,php,RoR,python,cobol,vb,vb.net

这是一个子集和问题.它是NP-Complete.

实现这一点的唯一方法是生成所有可能的组合并比较总和值.但是存在优化技术.

这是C#中的一个:

static class Program
{
    static int TargetSum = 10;
    static int[] InputData = new[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

    static void Main()
    {
        // find all permutations
        var permutations = Permute(InputData);

        // check each permutation for the sum
        foreach (var item in permutations) {

            if (item.Sum() == TargetSum) {

                Console.Write(string.Join(" + ", item.Select(n => n.ToString()).ToArray()));
                Console.Write(" = " + TargetSum.ToString());
                Console.WriteLine();

            }
        }

        Console.ReadKey();
    }

    static IEnumerable Permute(int[] data) { return Permute(data, 0); }

    static IEnumerable Permute(int[] data, int level)
    {
        // reached the edge yet? backtrack one step if so.
        if (level >= data.Length) yield break;

        // yield the first #level elements
        yield return data.Take(level + 1).ToArray();

        // permute the remaining elements
        for (int i = level + 1; i < data.Length; i++) {
            var temp = data[level];
            data[level] = data[i];
            data[i] = temp;

            foreach (var item in Permute(data, level + 1))
                yield return item;

            temp = data[i];
            data[i] = data[level];
            data[level] = temp;
        }

    }
}