Notes

// QUESTION Production binaries are release of an application by company X from time to time.

// Now the binaries follow transitive properties, which means if v1 is compatible with v2 and v2 is compatible with v3. v1 and v3 are also compatible.

// You are given signature of two APIs, which are required to be developed.

// void addVersion(version,isCompatible) - API takes input of binary version in version, and if this binary is compatible with immediate previous version.
// e.g., addVersion(2,true) -> version v2 is compatible with v1
// addVersion(3,false) -> version v3 is not compatible with v2

// - This API is used by company X
// bool isCompatible(srcVer,targetVer) - API provides checking of a source version ( INT srcVer) is compatible with a target version (INT target version).

// e.g., isCompatible(2,1) -> true : version 1 & 2 are compatible
// isCompatible(2,3) -> false: version 2 & 3 are not compatible
// Complete the API for the same.


const STARTING_BUCKET = 1

let latestVersion = 0;
let latestBucket = 0;
const versions = {
// // version: bucket,
// 1: 1,
// 2: 1,
// 3: 1,
// 4: 3
}

const bucketVersions = {
// bucket: bucketCompatibility
// 1: 1,
// 2: 6,
// 3: 3,
// 4: 4,
// 5: 6
}


function addVersion(newVersion, isCompatible) {
if (Object.keys(versions).length === 0) {
versions[newVersion] = STARTING_BUCKET;
bucketVersions[STARTING_BUCKET] = STARTING_BUCKET;
latestVersion = newVersion;
latestBucket = STARTING_BUCKET;
return
}

if (isCompatible) {
versions[newVersion] = versions[latestVersion];
}
else {
const newBucket = versions[latestVersion] + 1
versions[newVersion] = newBucket;
bucketVersions[newBucket] = bucketVersions[latestBucket] + 1;
latestBucket = newBucket;
}

latestVersion = newVersion;
}

function isCompatible(srcVersion, targetVersion) {
return versions[srcVersion] === versions[targetVersion] ||
bucketVersions[versions[srcVersion]] === bucketVersions[versions[targetVersion]]
}

function makeCompatible(srcVersion, targetVersion) {
const latestBucketCompatibility = bucketVersions[latestBucket];
const newBucketCompatibility = latestBucketCompatibility + 1;

bucketVersions[versions[srcVersion]] = newBucketCompatibility;
bucketVersions[versions[targetVersion]] = newBucketCompatibility;

latestBucket = versions[srcVersion];
}


// QUESTION: Extended question:

// There are few legacy binaries which are added to compatibility, so you need to make another API

// void makeCompatible(srcVer,tarVer)

// in which one makes a certain source version (srcVer) compatible with target version ( tarVer )


function main() {
addVersion(1,true)
addVersion(2,true)
addVersion(3,false)
addVersion(4,true)
addVersion(5,true)
addVersion(6,true)
addVersion(7,false)

// console.log(isCompatible(2,1))
// console.log(isCompatible(2,3))

console.log(isCompatible(4,5)) // T
console.log(isCompatible(6,5)) // T
console.log(isCompatible(4,6)) // T
console.log(isCompatible(3,7)) // F

makeCompatible(7, 5)
console.log(isCompatible(7, 5)) // T
console.log(isCompatible(7, 4)) // T
}

main()