401. Binary Watches binary Watch

A Binary Watch has 4 LEDs on the top which represent the hours (0-11), and the 6 LEDs on the bottom repr Esent the minutes (0-59).

Each LED represents a zero or one and the least significant bit on the right.

For example, the above binary watch reads "3:25".

Given a non-negative integer n which represents the number of LEDs that is currently on, return all possible Tim Es the watch could represent.

Example:

Input:n = 1
Return: ["1:00", "2:00", "4:00", "8:00", "0:01", "0:02", "0:04", "0:08", "0:16", "0:32")

Note:

• The order of output does not matter.
• The hour must not contain a leading zero, for example "01:00" are not valid and it should be "1:00".
• The minute must be consist of both digits and may contain a leading zero, for example "10:2" are not valid, it should be "10 : 02 ".

The number on the binary watch has one feature: After converting to binary, only 1 digits are 1 For example: 2=10 4=100
8=1000
This feature can be used to solve problems

  
 

   
  

  
static public List<string> ReadBinaryWatch(int num) {
   
  

  
List<string> list = new List<string>();
   
  

  
string s = "";
   
  

  
for (int i = 0; i < 12; i++) {
   
  

  
  for    ( int   J  =    0    J  <    60  ;   J  ++)    {  
   
  

  
  if    ( bitcount   (  I  )    +    Span class= "Typ" >bitcount   ( j   Span class= "PLN" >  ==   num  )    {  
   
  

  
list.Add(i.ToString() + ":" + NumberToString(j));
   
  

  
}
   
  

  
}
   
  

  
}
   
  

  
return list;
   
  

  
}
   
  

  

   
  

  
static public int BitCount(int number) {
   
  

  
int sum = 0;
   
  

  
while (number > 0) {
   
  

  
if ((number & 1) == 1) {
   
  

  
sum++;
   
  

  
}
   
  

  
number >>= 1;
   
  

  
}
   
  

  
return sum;
   
  

  
}
   
  

  

   
  

  
static public string NumberToString(int number) {
   
  

  
string s = number.ToString();
   
  

  
return s.PadLeft(2, ‘0‘);
   
  

  
}
  
 

From for notes (Wiz)

401. Binary Watches binary Watch