I have a string:
string input = "aaaabbcccghbcccciippppkkllk"
The output should be:
abcghbcipklk
Note: Must use loop or recursion. etc.
Just want to know is there better and efficient code than this:
string input = "aaaabbcccghbcccciippppkkllk";
int j=0;
for (int i=0; i<input.Length - 1; i++) {
for(j=i+1; j<input.Length && input[i] == input[j]; j++);
input = input.Substring(0, i+1) + input.Substring(j);
}
Console.WriteLine(input);
According to my understanding, you want to eliminate duplicates only if it is in a consecutive sequence. You could achieve it using the following
Using List<string>
var nonDuplicates = new List<char>();
foreach (var element in str.ToCharArray())
{
if(nonDuplicates.Count == 0 || nonDuplicates.Last() != element)
nonDuplicates.Add(element);
}
var result = new string(nonDuplicates.ToArray());
Update
With reference to comment from , I have updated and the answer with two more solutions and ran the benchmark on them. The results are shown below.
Using String Append
var str = "aaaabbcccghbcccciippppkkllk";
var strResult = string.Empty;
foreach (var element in str.ToCharArray())
{
if (strResult.Length == 0 || strResult[strResult.Length - 1] != element)
strResult = $"{strResult}{element}";
}
Using StringBuilder
var str = "aaaabbcccghbcccciippppkkllk";
var strResult = new StringBuilder();
foreach (var element in str.ToCharArray())
{
if (strResult.Length == 0 || strResult[strResult.Length - 1] != element)
strResult.Append(element);
}
var result = strResult.ToString();
Benchmark Results
Method | Mean | Error | StdDev | Median |
------------------- |-----------:|----------:|-----------:|-----------:|
UsingList | 809.7 ns | 11.975 ns | 11.202 ns | 806.5 ns |
UsingStringAppend | 1,738.0 ns | 39.269 ns | 109.467 ns | 1,697.2 ns |
UsingStringBuilder | 201.6 ns | 1.960 ns | 1.834 ns | 201.1 ns |
As seen in the results, the StrinbBuilder Approach is much fast when compared to List. The string append approach is slowest.
Input
aaaabbcccghbcccciippppkkllk
Output
abcghbcipklk
Ok, here is how you can do that using "simple" language:
string input = "aaaabbcccghbcccciippppkkllk"
var result = "" + input[0];
for(var i = 1; i < input.Length; i++)
{
if(input[i] != result[result.Length-1])
{
result += input[i];
}
}
string str = "abbxxcccxbaac";
string nstr = str[0].ToString();
for(int j = 0; j < str.Length - 1; j++)
{
if(!str[j].Equals(str[j + 1]))
{
nstr = nstr + str[j + 1];
}
}
It will remove sequential char from the string. nstr is output.
