Files
Rob Simpson 39d01138ec Abbreviation (#1547)
* Abbreviation

* Updates from code review
2023-11-15 19:25:30 +05:30

48 lines
2.0 KiB
JavaScript

/**
* @description
* Given two strings, `source` and `target`, determine if it's possible to make `source` equal
* to `target` You can perform the following operations on the string `source`:
* 1. Capitalize zero or more of `source`'s lowercase letters.
* 2. Delete all the remaining lowercase letters in `source`.
*
* Time Complexity: (O(|source|*|target|)) where `|source|` => length of string `source`
*
* @param {String} source - The string to be transformed.
* @param {String} target - The string we want to transform `source` into.
* @returns {Boolean} - Whether the transformation is possible.
* @see https://www.hackerrank.com/challenges/abbr/problem - Related problem on HackerRank.
*/
export const isAbbreviation = (source, target) => {
const sourceLength = source.length
const targetLength = target.length
// Initialize a table to keep track of possible abbreviations
let canAbbreviate = Array.from({ length: sourceLength + 1 }, () =>
Array(targetLength + 1).fill(false)
)
// Empty strings are trivially abbreviatable
canAbbreviate[0][0] = true
for (let sourceIndex = 0; sourceIndex < sourceLength; sourceIndex++) {
for (let targetIndex = 0; targetIndex <= targetLength; targetIndex++) {
if (canAbbreviate[sourceIndex][targetIndex]) {
// If characters at the current position are equal, move to the next position in both strings.
if (
targetIndex < targetLength &&
source[sourceIndex].toUpperCase() === target[targetIndex]
) {
canAbbreviate[sourceIndex + 1][targetIndex + 1] = true
}
// If the current character in `source` is lowercase, explore two possibilities:
// a) Capitalize it (which is akin to "using" it in `source` to match `target`), or
// b) Skip it (effectively deleting it from `source`).
if (source[sourceIndex] === source[sourceIndex].toLowerCase()) {
canAbbreviate[sourceIndex + 1][targetIndex] = true
}
}
}
}
return canAbbreviate[sourceLength][targetLength]
}