33 lines
1.3 KiB
Markdown
33 lines
1.3 KiB
Markdown
### levenshteinDistance
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Calculates the [Levenshtein distance](https://en.wikipedia.org/wiki/Levenshtein_distance) between two strings.
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Calculates the number of changes (substitutions, deletions or additions) required to convert `string1` to `string2`.
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Can also be used to compare two strings as shown in the second example.
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``` js
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const levenshteinDistance = (string1, string2) => {
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if(string1.length === 0) return string2.length;
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if(string2.length === 0) return string1.length;
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let matrix = Array(string2.length + 1).fill(0).map((x,i) => [i]);
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matrix[0] = Array(string1.length + 1).fill(0).map((x,i) => i);
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for(let i = 1; i <= string2.length; i++){
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for(let j = 1; j<=string1.length; j++){
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if(string2[i-1] === string1[j-1]){
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matrix[i][j] = matrix[i-1][j-1];
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}
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else{
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matrix[i][j] = Math.min(matrix[i-1][j-1]+1, matrix[i][j-1]+1, matrix[i-1][j]+1);
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}
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}
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}
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return matrix[string2.length][string1.length];
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};
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```
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```js
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levenshteinDistance('30-seconds-of-code','30-seconds-of-python-code'); // 7
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const compareStrings = (string1,string2) => (100 - levenshteinDistance(string1,string2) / Math.max(string1.length,string2.length));
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compareStrings('30-seconds-of-code', '30-seconds-of-python-code'); // 99.72 (%)
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```
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