Levenshtein distance/Alignment: Difference between revisions

added java
(added java)
Line 189:
fa := align.Format(a, b, aln, '-')
fmt.Printf("%s\n%s\n", fa[0], fa[1])
}</lang>
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<pre>
r-oset-tacode
raisethysword
</pre>
 
=={{header|Java}}==
<lang java>public class LevenshteinAlignment {
 
public static String[] alignment(String a, String b) {
a = a.toLowerCase();
b = b.toLowerCase();
// i == 0
int[][] costs = new int[a.length()+1][b.length()+1];
for (int j = 0; j <= b.length(); j++)
costs[0][j] = j;
for (int i = 1; i <= a.length(); i++) {
costs[i][0] = i;
for (int j = 1; j <= b.length(); j++) {
costs[i][j] = Math.min(1 + Math.min(costs[i-1][j], costs[i][j-1]), a.charAt(i - 1) == b.charAt(j - 1) ? costs[i-1][j-1] : costs[i-1][j-1] + 1);
}
}
 
// walk back through matrix to figure out path
StringBuilder aPathRev = new StringBuilder();
StringBuilder bPathRev = new StringBuilder();
for (int i = a.length(), j = b.length(); i != 0 && j != 0; ) {
if (costs[i][j] == (a.charAt(i - 1) == b.charAt(j - 1) ? costs[i-1][j-1] : costs[i-1][j-1] + 1)) {
aPathRev.append(a.charAt(--i));
bPathRev.append(b.charAt(--j));
} else if (costs[i][j] == 1 + costs[i-1][j]) {
aPathRev.append(a.charAt(--i));
bPathRev.append('-');
} else if (costs[i][j] == 1 + costs[i][j-1]) {
aPathRev.append('-');
bPathRev.append(b.charAt(--j));
}
}
return new String[]{aPathRev.reverse().toString(), bPathRev.reverse().toString()};
}
 
public static void main(String[] args) {
String[] result = alignment("rosettacode", "raisethysword");
System.out.println(result[0]);
System.out.println(result[1]);
}
}</lang>
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