String Counter

Mittal Sejpal

15y1.9k.NET

I wanna Create a String incrementer
Like a to b
aa to ab
etc

3 Replies

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Vulpes15y ago
OK, then try instead:

using System;

class Program
{
static void Main()
{
string[] samples = {"a", "aa", "aaa", "aaaa", "z", "zz", "zzz", "zzzz"};

foreach(string s in samples)
{
string t = IncrementString(s);
Console.WriteLine(t);
}
Console.ReadKey();
}

static string IncrementString(string s)
{
// if s is invalid return an empty string, say
if (String.IsNullOrEmpty(s)) return "";

int len = s.Length;

// the string should only contain lower case letters
for(int i = 0; i < len; i++)
{
if (s[i] < 'a' || s[i] > 'z') return "";
}

// check if it contains all z's
bool allZ = true;

for(int i = 0; i < len; i++)
{
if (s[i] != 'z')
{
allZ = false;
break;
}
}

if (allZ) return new string('a', len + 1);

int multiplier = 1;
int code = 0;

for (int i = len - 1; i >= 0; i--)
{
code += (s[i] - 97) * multiplier;
multiplier *= 26;
}

code++;
char[] chars = new char[len];

for(int i = len - 1; i >= 0; i--)
{
chars[i] = (char)(code % 26 + 97);
code /= 26;
}

return new string(chars);
}
}
Mittal Sejpal15y ago
No but i want the format i.e z - aa zz- aaa
Vulpes15y ago
Try the following:

using System;

class Program
{
static void Main()
{
string[] samples = {"a", "aa", "aaa", "aaaa", "z", "ad", "bcd", "zxxy"};

foreach(string s in samples)
{
string t = IncrementString(s);
Console.WriteLine(t);
}
Console.ReadKey();
}

static string IncrementString(string s)
{
// if s is invalid return an empty string, say
if (String.IsNullOrEmpty(s)) return "";

int len = s.Length;

// the string should only contain lower case letters
for(int i = 0; i < len; i++)
{
if (s[i] < 'a' || s[i] > 'z') return "";
}

int multiplier = 1;
int code = 0;

for (int i = len - 1; i >= 0; i--)
{
code += (s[i] - 97) * multiplier;
multiplier *= 26;
}

code++;
char[] chars = new char[len];

for(int i = len - 1; i >= 0; i--)
{
chars[i] = (char)(code % 26 + 97);
code /= 26;
}

return new string(chars);
}
}

Note that when you get to "z", "zz" etc. the method as it stands will return the next string as "a", "aa" etc.