c# 编程题，大佬直接留下代码，输入字符串（可以是字母也可以是数字）输出所有子字符串不能用递归等

Question

Write a program that reads a string from standard input. The string will appear on a single line, and will contain no whitespace characters. You may assume that all characters in the string are unique.

Your program should print out all non-empty subsequences of characters that can be formed from the characters in the input string. Write each subsequence on a separate line. The characters in each subsequence must appear in the same order as in the original string. You may write the subsequences in any order.

Important: All of your code must appear in Main(); you may not write any other functions/methods (nested or otherwise). After all, we haven't learned about writing methods in C# yet. :) And so you may not use recursion to solve this problem as we did in Programming 1.

Sample input:

jump

Possible output:

j
u
ju
m
jm
um
jum
p
jp
up
jup
mp
jmp
ump
jump

Hint: If N is the length of the input string, there are 2^N possible subsequences (including the empty sequence). That's because each of the N input letters either is or is not in the output, so there are 2 possibilities for that letter.

There also happen to be 2^N numbers that can be written using N digits in binary representation (i.e. base 2). If you can generate those binary numbers, you can use each one to generate an output string (excepting the empty string).

Answer 1

using System;
namespace HelloWorldApplication
{
    class HelloWorld
    {
        static void Main(string[] args)
        {
            /* 我的第一个 C# 程序*/
			String line;
            //line="jump";
			line = Console.ReadLine();
			int n = line.Length;
			long  maxn = 1 << n;
			for(int i = 0; i < maxn; i++){
				for(int j = 0; j < n; j++){
					long mask = 1 << j;
					long masked = i & mask;
					if(masked!=0){
						Console.Write(line[j]);
					}
				}
				Console.Write("\n");
			}
        }
    }
}