Burrows–Wheeler transform: Difference between revisions
→{{header|Julia}}
(Add Swift) |
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Line 701:
SIX.MIXED.PIXIES.SIFT.SIXTY.PIXIE.DUST.BOXES
</pre>
=={{header|Java}}==
{{trans|Kotlin}}
<lang java>import java.util.ArrayList;
import java.util.List;
public class BWT {
private static final String STX = "\u0002";
private static final String ETX = "\u0003";
private static String bwt(String s) {
if (s.contains(STX) || s.contains(ETX)) {
throw new IllegalArgumentException("String cannot contain STX or ETX");
}
String ss = STX + s + ETX;
List<String> table = new ArrayList<>();
for (int i = 0; i < ss.length(); i++) {
String before = ss.substring(i);
String after = ss.substring(0, i);
table.add(before + after);
}
table.sort(String::compareTo);
StringBuilder sb = new StringBuilder();
for (String str : table) {
sb.append(str.charAt(str.length() - 1));
}
return sb.toString();
}
private static String ibwt(String r) {
int len = r.length();
List<String> table = new ArrayList<>();
for (int i = 0; i < len; ++i) {
table.add("");
}
for (int j = 0; j < len; ++j) {
for (int i = 0; i < len; ++i) {
table.set(i, r.charAt(i) + table.get(i));
}
table.sort(String::compareTo);
}
for (String row : table) {
if (row.endsWith(ETX)) {
return row.substring(1, len - 1);
}
}
return "";
}
private static String makePrintable(String s) {
// substitute ^ for STX and | for ETX to print results
return s.replace(STX, "^").replace(ETX, "|");
}
public static void main(String[] args) {
List<String> tests = List.of(
"banana",
"appellee",
"dogwood",
"TO BE OR NOT TO BE OR WANT TO BE OR NOT?",
"SIX.MIXED.PIXIES.SIFT.SIXTY.PIXIE.DUST.BOXES",
"\u0002ABC\u0003"
);
for (String test : tests) {
System.out.println(makePrintable(test));
System.out.print(" --> ");
String t = "";
try {
t = bwt(test);
System.out.println(makePrintable(t));
} catch (IllegalArgumentException e) {
System.out.println("ERROR: " + e.getMessage());
}
String r = ibwt(t);
System.out.printf(" --> %s\n\n", r);
}
}
}</lang>
{{out}}
<pre>banana
--> |annb^aa
--> banana
appellee
--> |e^elplepa
--> appellee
dogwood
--> |do^oodwg
--> dogwood
TO BE OR NOT TO BE OR WANT TO BE OR NOT?
--> |?OOORREEETTRTW BBB ATTT NNOOONOO^
--> TO BE OR NOT TO BE OR WANT TO BE OR NOT?
SIX.MIXED.PIXIES.SIFT.SIXTY.PIXIE.DUST.BOXES
--> |STEXYDST.E.IXXIIXXSSMPPS.B..EE.^.USFXDIIOIIIT
--> SIX.MIXED.PIXIES.SIFT.SIXTY.PIXIE.DUST.BOXES
^ABC|
--> ERROR: String cannot contain STX or ETX
--> </pre>
=={{header|Julia}}==
| |||