const binarySearchByProperty = (obj, target, property) => {
const n = obj.length
// Corner cases
if (target <= obj[0][property]) {
return obj[0];
}
if (target >= obj[n - 1][property]) {
return obj[n - 1];
}
// Doing binary search
let i = 0, j = n, mid = 0;
while (i < j) {
mid = Math.floor((i + j) / 2)
if (obj[mid][property] == target) {
return obj[mid];
}
/* If target is less than array element,
then search in left */
if (target < obj[mid][property]) {
// If target is greater than previous
// to mid, return closest of two
if (mid > 0 && target > obj[mid - 1][property]) {
return binarySearchByPropertyGetClosest(obj[mid - 1], obj[mid], target, property);
}
/* Repeat for left half */
j = mid;
} else {
// If target is greater than mid
if (mid < n - 1 && target < obj[mid + 1][property]) {
return binarySearchByPropertyGetClosest(obj[mid], obj[mid + 1], target, property);
}
// update i
i = mid + 1;
}
}
// Only single element left after search
return obj[mid];
}
const binarySearchByPropertyGetClosest = (val1, val2, target, property) => {
if (target - val1[property] >= val2[property] - target) {
return val2;
} else {
return val1;
}
}
const binarySearchByValue = (obj, target) => {
const n = obj.length
// Corner cases
if (target <= obj[0]) {
return obj[0];
}
if (target >= obj[n - 1]) {
return obj[n - 1];
}
// Doing binary search
let i = 0, j = n, mid = 0;
while (i < j) {
mid = Math.floor((i + j) / 2)
if (obj[mid] == target) {
return obj[mid];
}
/* If target is less than array element,
then search in left */
if (target < obj[mid]) {
// If target is greater than previous
// to mid, return closest of two
if (mid > 0 && target > obj[mid - 1]) {
return binarySearchByValueGetClosest(obj[mid - 1], obj[mid], target);
}
/* Repeat for left half */
j = mid;
} else {
// If target is greater than mid
if (mid < n - 1 && target < obj[mid + 1]) {
return binarySearchByValueGetClosest(obj[mid], obj[mid + 1], target);
}
// update i
i = mid + 1;
}
}
// Only single element left after search
return obj[mid];
}
const binarySearchByValueGetClosest = (val1, val2, target) => {
if (target - val1 >= val2 - target) {
return val2;
} else {
return val1;
}
}
const worker = async (options) => {
const { Worker } = require('worker_threads');
const workerResult = await new Promise((resolve, reject) => {
const worker = new Worker(`${__dirname}/worker.js`, {
workerData: options
});
worker.on('message', resolve);
worker.on('error', reject);
worker.on('exit', (code) => {
if (code !== 0) {
reject(new Error(`Worker stopped with exit code ${code}`));
}
worker.terminate()
});
});
return workerResult
};
module.exports.binarySearchByProperty = binarySearchByProperty
module.exports.binarySearchByValue = binarySearchByValue
module.exports.worker = worker
