-
Notifications
You must be signed in to change notification settings - Fork 3
/
util.js
68 lines (58 loc) · 1.73 KB
/
util.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
/// util
// Given a list of items that may contain duplicates,
// return an updated copy of the list without any duplicates.
function distinct(items){
return items.filter((val, idx) => items.indexOf(val) === idx);
}
function randNth(items){
return items[Math.floor(Math.random()*items.length)];
}
function partition(list, partitionSize) {
const partitions = [];
let currPartition = [];
for (let item of list) {
currPartition.push(item);
if (currPartition.length >= partitionSize) {
partitions.push(currPartition);
currPartition = [];
}
}
if (currPartition.length > 0) {
partitions.push(currPartition);
}
return partitions;
}
// from https://gist.github.com/andrei-m/982927
// Compute the edit distance between the two given strings
function getEditDistance(a, b){
if(a.length == 0) return b.length;
if(b.length == 0) return a.length;
var matrix = [];
// increment along the first column of each row
var i;
for(i = 0; i <= b.length; i++){
matrix[i] = [i];
}
// increment each column in the first row
var j;
for(j = 0; j <= a.length; j++){
matrix[0][j] = j;
}
// Fill in the rest of the matrix
for(i = 1; i <= b.length; i++){
for(j = 1; j <= a.length; j++){
if(b.charAt(i-1) == a.charAt(j-1)){
matrix[i][j] = matrix[i-1][j-1];
} else {
matrix[i][j] = Math.min(matrix[i-1][j-1] + 1, // substitution
Math.min(matrix[i][j-1] + 1, // insertion
matrix[i-1][j] + 1)); // deletion
}
}
}
return matrix[b.length][a.length];
};
function getNormalizedEditDistance(a, b) {
const editDistance = getEditDistance(a, b);
return editDistance / Math.max(a.length, b.length);
}