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React - Lifting State

Jan 25, 2023C S
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URL Search Term Generator

Jan 17, 2021C S

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const getSearchTerm = delimiter => {
let searchTerm = "";
for (let i = 1; i < commands.length - 1; i++)
searchTerm = searchTerm + commands[i] + delimiter;
searchTerm += commands[commands.length - 1];
return searchTerm;
};

find primes

Nov 19, 2022CodeCatch

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const primes = num => {
let arr = Array.from({ length: num - 1 }).map((x, i) => i + 2),
sqroot = Math.floor(Math.sqrt(num)),
numsTillSqroot = Array.from({ length: sqroot - 1 }).map((x, i) => i + 2);
numsTillSqroot.forEach(x => (arr = arr.filter(y => y % x !== 0 || y === x)));
return arr;
};
primes(10); // [2, 3, 5, 7]

LeetCode Contains Duplicate

Sep 13, 2023C S

0 likes • 2 views

/**
* @param {number[]} nums
* @return {boolean}
*/
var containsDuplicate = function(nums) {
return new Set(nums).size !== nums.length
};

LeetCode Two Sum

Sep 13, 2023C S

0 likes • 2 views

/**
* @param {number[]} nums
* @param {number} target
* @return {number[]}
*/
var twoSum = function(nums, target) {
for(let i = 0; i < nums.length; i++) {
for(let j = 0; j < nums.length; j++) {
if(nums[i] + nums[j] === target && i !== j) {
return [i, j]
}
}
}
};

Get timezone as a string

Nov 19, 2022CodeCatch

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const getTimezone = () => Intl.DateTimeFormat().resolvedOptions().timeZone;
// Example
getTimezone();

kNearestNeighbors

Nov 19, 2022CodeCatch

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const kNearestNeighbors = (data, labels, point, k = 3) => {
const kNearest = data
.map((el, i) => ({
dist: Math.hypot(...Object.keys(el).map(key => point[key] - el[key])),
label: labels[i]
}))
.sort((a, b) => a.dist - b.dist)
.slice(0, k);
return kNearest.reduce(
(acc, { label }, i) => {
acc.classCounts[label] =
Object.keys(acc.classCounts).indexOf(label) !== -1
? acc.classCounts[label] + 1
: 1;
if (acc.classCounts[label] > acc.topClassCount) {
acc.topClassCount = acc.classCounts[label];
acc.topClass = label;
}
return acc;
},
{
classCounts: {},
topClass: kNearest[0].label,
topClassCount: 0
}
).topClass;
};
const data = [[0, 0], [0, 1], [1, 3], [2, 0]];
const labels = [0, 1, 1, 0];
kNearestNeighbors(data, labels, [1, 2], 2); // 1
kNearestNeighbors(data, labels, [1, 0], 2); // 0