#### KMP Pattern Searching

P
```// Implementing KMP Search Algorithm to search all the instances of pattern in
// given text
// Reference Book: Introduction to Algorithms, CLRS

// Explanation: https://www.topcoder.com/community/competitive-programming/tutorials/introduction-to-string-searching-algorithms/

const computeLPS = (pattern) => {
const lps = Array(pattern.length)
lps[0] = 0
for (let i = 1; i < pattern.length; i++) {
let matched = lps[i - 1]
while (matched > 0 && pattern[i] !== pattern[matched]) {
matched = lps[matched - 1]
}
if (pattern[i] === pattern[matched]) {
matched++
}
lps[i] = matched
}
return lps
}

/**
* Returns all indices where pattern starts in text
* @param {*} text a big text in which pattern string is to find
* @param {*} pattern the string to find
*/
const KMPSearch = (text, pattern) => {
if (!pattern || !text) {
}

// lps[i] = length of proper prefix of pattern[0]...pattern[i-1]
//          which is also proper suffix of it
const lps = computeLPS(pattern)
const result = []

let matched = 0
for (let i = 0; i < text.length; i++) {
while (matched > 0 && text[i] !== pattern[matched]) {
matched = lps[matched - 1]
}
if (text[i] === pattern[matched]) {
matched++
}
if (matched === pattern.length) {
result.push(i - pattern.length + 1)
matched = lps[matched - 1]
}
}

return result
}

export { KMPSearch }
```