数字排列问题 。
比如
一个4个字的号码 ， 1234
可以组合出 24 个号码 , 2134,3124,4123 ...等等
有没有人有写好的方法？
之前自己写的
public static ArrayList digitalReorganization(string number)//不一定要是number
{
int length = number.Length;
Array distinct = number.ToArray().Distinct().ToArray();
string mode = "part1";
if (length != distinct.Length) mode = "part2"; //2种方法，重复的话可以使用第2种
ArrayList result = new ArrayList();
result.Add(number);
for (int i = 0; i < number.Length - 1; i++)
{
if (mode == "part1") result = digitalReorganizationSort(result, i);
else result = digitalReorganizationSortPart2(result, i);
}
if (mode == "part1") result = new ArrayList(result.ToArray().Distinct().ToArray()); //需要过滤掉重复的
return result;
}
public static ArrayList digitalReorganizationSort(ArrayList numberlist, int index)
{
int loop_count = numberlist.Count;
for (var i = 0; i < loop_count; i++)
{
ArrayList old = new ArrayList(numberlist[i].ToString().ToArray());
for (var j = 0; j < old.Count - 1 - index; j++)
{
ArrayList temp = new ArrayList(numberlist[i].ToString().ToArray()); //每次copy一个来对调位置
string word = old[index].ToString();
string next = old[index + j + 1].ToString();
temp[index] = next;
temp[index + j + 1] = word;
string new_number = String.Join("", temp.ToArray());
numberlist.Add(new_number);
}
}
return numberlist;
}
public static ArrayList digitalReorganizationSortPart2(ArrayList numberlist, int index)
{
int loop_count = numberlist.Count;
for (var i = 0; i < loop_count; i++)
{
ArrayList old = new ArrayList(numberlist[i].ToString().ToArray());
ArrayList distinct_number = new ArrayList(numberlist[i].ToString().Substring(index).ToArray().Distinct().ToArray());
for (var j = 0; j < distinct_number.Count - 1; j++)
{
string distinct_word = distinct_number[j + 1].ToString();
int target = Array.IndexOf(old.ToArray(), distinct_word.ToArray()[0], index);
string word = old[index].ToString();
string next = old[target].ToString();
ArrayList temp = new ArrayList(numberlist[i].ToString().ToArray());
temp[index] = next;
temp[target] = word;
string new_number = String.Join("", temp.ToArray());
numberlist.Add(new_number);
}
}
return numberlist;
}
string number = "1234";
ArrayList new_number = stooges.digitalReorganization(number);
