sorting - Java Bucket Sort on Strings - Stack Overflow
Sort by the first character. This gives you some number of "buckets." Sort each nonempty bucket starting with the second character. Repeat until the whole thing is sorted.
public void bucketSort(String[] words)
{
int maxlength=0;
for(int i=0;i<words.length;i++)
{
words[i] = words[i].toUpperCase();
if(maxlength<words[i].length())
maxlength = words[i].length();
}
for(int j=maxlength-1;j>=0;j--)
{
Vector<Vector<String>> map = new Vector<Vector<String>>();
for(int i=0;i<27;i++)
{
map.add(null);
}
for(int i=0;i<words.length;i++)//Add words of of length j or greater to map(which is bucket here)
{
if(words[i].length()>j)
{
int val = (int)words[i].charAt(j) -65;
if(map.get(val)!= null)
{
map.get(val).add(words[i]);
}
else
{
Vector<String> vecot = new Vector<String>();
vecot.add(words[i]);
map.add(val, vecot);
}
}
else///Add words of of length<j to bucket 0
{
if(map.get(0) != null)
{
map.get(0).add(words[i]);
}
else
{
Vector<String> vecot = new Vector<String>();
vecot.add(words[i]);
map.add(0, vecot);
}
}
}
int count =0;
for(int i=0;i<map.size();i++)
{
if(map.get(i)!=null)
{
for(int k=0;k<map.get(i).size();k++)
{
words[count]=map.get(i).get(k);
count++;
}
}
}
System.out.println("Next set :");
for(int i=0;i<words.length;i++)
{
System.out.println(words[i]);
}
}
}