# Compute Levenshtein distance : String Compare « Data Type « Java

Compute Levenshtein distance

```
/*   Copyright 2004 The Apache Software Foundation
*
*   you may not use this file except in compliance with the License.
*   You may obtain a copy of the License at
*
*
*   Unless required by applicable law or agreed to in writing, software
*   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*   See the License for the specific language governing permissions and
*/
//based on Apache technology http://www.apache.org
public class Levenshtein {
// ****************************
// Get minimum of three values
// ****************************

private static int minimum(int a, int b, int c) {
int mi = a;
if (b < mi)
mi = b;
if (c < mi)
mi = c;
return mi;
}

// *****************************
// Compute Levenshtein distance
// *****************************
public static int distance(String s, String t) {
int d[][]; // matrix
int n; // length of s
int m; // length of t
int i; // iterates through s
int j; // iterates through t
char s_i; // ith character of s
char t_j; // jth character of t
int cost; // cost

// Step 1
n = s.length();
m = t.length();
if (n == 0)
return m;
if (m == 0)
return n;
d = new int[n + 1][m + 1];

// Step 2
for (i = 0; i <= n; i++)
d[i][0] = i;
for (j = 0; j <= m; j++)
d[0][j] = j;

// Step 3
for (i = 1; i <= n; i++) {
s_i = s.charAt(i - 1);

// Step 4
for (j = 1; j <= m; j++) {
t_j = t.charAt(j - 1);

// Step 5
if (s_i == t_j)
cost = 0;
else
cost = 1;

// Step 6
d[i][j] = minimum(d[i - 1][j] + 1, d[i][j - 1] + 1, d[i - 1][j - 1] + cost);
}
}

// Step 7
return d[n][m];
}

}

```

### Related examples in the same category

 1 How to compare String instances 2 String.compareTo 3 Check order of two strings 4 Check order of two strings ignoring case 5 Compare Strings 6 Comparing Strings 7 A string can be compared with a StringBuffer 8 Compares all Strings in an array and returns the index at which the Strings begin to differ. 9 Compares all Strings in an array and returns the initial sequence of characters that is common to all of them. 10 Compares two Strings, and returns the index at which the Strings begin to differ. 11 Compares two Strings, and returns the portion where they differ. 12 Compares two Strings, returning true if they are equal ignoring the case. 13 Compares two Strings, returning true if they are equal. 14 Compress 2 adjacent (single or double) quotes into a single (s or d) quote when found in the middle of a String. 15 Find the Levenshtein distance between two Strings. 16 Compare two String[] for differences, either may be null 17 count Occurrences 18 Returns the length of the longest shared prefix of the two input strings. 19 Compares two strings: recognizes and handles embedded numbers. 20 Returns the levenshtein distance of two strings