Muhammad Khan

export const nearestPerfectMonths = (year: number) => { const result = { prev: new Date(year, 0, 1), next: new Date(year + 1, 0, 1) }; while (![4, 5].includes(result.prev.getDay())) { result.prev = new Date(result.prev.getFullYear() - 1, 0, 1); } while (![4, 5].includes(result.next.getDay())) { result.next = new Date(result.next.getFullYear() + 1, 0, 1); } return { prev: `${result.prev.getFullYear()}-02`, next: `${result.next.getFullYear()}-02`, }; };

github.com/muhammadk160...

const countVowels = (word: string) => word.match(/[aeiou]/gi)?.length || 0; export const flippedy = (str: string) => { const words = str.split(" "); const firstWord = words[0]; if (!firstWord) return str; const vowelCount = countVowels(firstWord); return words.reduce((acc, word) => { if (countVowels(word) === vowelCount) { return acc + " " + word.split("").reverse().join(""); } return acc + " " + word; }); };

github.com/muhammadk160...

export const hungryBears = (bears: { name: string; hunger: number }[]) => bears .filter(bear => bear.hunger > bears.reduce((sum, bear) => sum + bear.hunger, 0) / bears.length) .sort((a, b) => a.name.localeCompare(b.name)) .map(bear => bear.name);

github.com/muhammadk160...

I consider this a one-liner, :)

export const sumOfNeighbors = (arr: number[]): number => { let sum = 0; for (let i = 0; i < arr.length; i++) { sum += (arr[i - 1] || 0) + (arr[i] || 0) + (arr[i + 1] || 0); } return sum; };

github.com/muhammadk160...

export const canFormHexagon = (sides: number[]): boolean => { if (sides.length !== 6) return false; const sideCount: Record<number, number> = {}; for (const side of sides) { sideCount[side] = (sideCount[side] || 0) + 1; } return Object.values(sideCount).filter(count => count >= 2).length === 3; };

github.com/muhammadk160...

Hexagons are Bestagons!

export const nonRepeat = (str: string): string => { const charCount: Record<string, number> = {}; for (const char of str) { charCount[char] = (charCount[char] || 0) + 1; } for (let i = str.length - 1; i >= 0; i--) { const char = str[i] || ""; if (charCount[char] === 1) return char; } return ""; };

github.com/muhammadk160...

const ROMAN_MAP = { I: 1, V: 5, X: 10, L: 50, C: 100, D: 500, M: 1000, } as const; const romanToInt = (roman: string): number => { let total = 0; let prevValue = 0; for (let i = roman.length - 1; i >= 0; i--) { const currentValue = ROMAN_MAP[roman[i] as keyof typeof ROMAN_MAP]; if (currentValue < prevValue) total -= currentValue; else total += currentValue; prevValue = currentValue; } return total; }; export const sortMonarchs = (monarchs: string[]): string[] => { return monarchs.sort((a, b) => { const [nameA, ordinalA] = a.split(" ") as [string, string]; const [nameB, ordinalB] = b.split(" ") as [string, string]; const numberA = romanToInt(ordinalA); const numberB = romanToInt(ordinalB); // If years are the same, compare by name return nameA.localeCompare(nameB) || numberA - numberB; }); };

github.com/muhammadk160...

GitHub - muhammadk1607/sbp-war-api: This is an API that returns weighted average buying and selling rates of major foreign currencies against the Pakistani Rupee (provided by State Bank of Pakistan). This is an API that returns weighted average buying and selling rates of major foreign currencies against the Pakistani Rupee (provided by State Bank of Pakistan). - muhammadk1607/sbp-war-api

Source Code at: github.com/muhammadk160...

I just released a new publicly available API

This API bridges that gap.

- Programmatic access to SBP daily weighted average buying rates (in JSON format)
- Updated daily at 4:00 PM PKT (excluding Bank Holidays)
- Built with FastAPI

Try it out: sbp-war-api.muhammadkhan.dev/docs

export type TrafficLight = "red" | "green" | "yellow"; export const isValidTrafficSequence = (sequence: TrafficLight[]): boolean => { let prevLight: TrafficLight | null = null; for (let i = 0; i < sequence.length; i++) { const light = sequence[i] as TrafficLight; if (prevLight === "red" && light !== "green") return false; if (prevLight === "green" && light !== "yellow") return false; if (prevLight === "yellow" && light !== "red") return false; prevLight = light; } return true; };

github.com/muhammadk160...

export const nestArray = (array: any[]): any[] => { const result: any[] = []; let current = result; for (let i = 0; i < array.length; i++) { current.push(array[i]); if (i === array.length - 1) break; const nextLevel: any[] = []; current.push(nextLevel); current = nextLevel; } return result; };

github.com/muhammadk160...

I have only one question regarding this task: "But why?"

export const oddSum = (first: number[], second: number[]): number[][] => { const result: number[][] = []; first.forEach(x => { second.forEach(y => { if ((x + y) % 2 !== 0) { result.push([x, y]); } }); }); return result; };

github.com/muhammadk160...

const CORNER = "+"; const VERTICAL = "|"; const HORIZONTAL = "-"; const DIAGONAL = "/"; const SPACE = " "; const NUMBER_OF_HORIZONTAL_LINES = 3; export const drawCube = (size: number) => { const horizontalLine = Array.from({ length: size * 2 + 2 }) .map((_, i, { length }) => (i === 0 || i === length - 1 ? CORNER : HORIZONTAL)) .join(""); const padding = Math.floor(size / 2); const rows = Array.from({ length: size + NUMBER_OF_HORIZONTAL_LINES + padding }); return ( "\n" + rows .map((_, i, { length }) => { if (i === 0) { return SPACE.repeat(padding + 1) + horizontalLine; } else if (i > 0 && i < padding + 1) { return ( SPACE.repeat(padding + 1 - i) + DIAGONAL + SPACE.repeat(size * 2) + DIAGONAL + SPACE.repeat(Math.max(i - 1, 0)) + VERTICAL ); } else if (i === padding + 1) { return horizontalLine + SPACE.repeat(padding) + VERTICAL; } else if (i > padding + 1 && i < length - 1) { let endItem = VERTICAL; let paddingEnd = padding; if (i === size + 1) { endItem = CORNER; } if (i > size + 1) { endItem = DIAGONAL; paddingEnd = length - i - 2; } return VERTICAL + SPACE.repeat(size * 2) + VERTICAL + SPACE.repeat(paddingEnd) + endItem; } else if (i === length - 1) { return horizontalLine; } else { return SPACE; } }) .join("\n") + "\n" ); };

Baseline shamelessly "borrowed" from @tenzhiyang.com

github.com/muhammadk160...

export const addOperators = (origin: number, target: number): string[] => { const digits = origin.toString().split(""); const result: string[] = []; const dfs = (index: number, path: string, currentNumber: number) => { if (index === digits.length) { if (currentNumber === target) result.push(path); return; } for (let i = index; i < digits.length; i++) { const digit = digits[i]; const newNumber = Number(digit); dfs(i + 1, `${path}+${digit}`, currentNumber + newNumber); dfs(i + 1, `${path}-${digit}`, currentNumber - newNumber); // Multiply but only if BODMAS is not violated if (!(path.includes("+") || path.includes("-"))) dfs(i + 1, `${path}*${digit}`, currentNumber * newNumber); } }; // Start DFS from the first digit const firstDigit = digits[0] as string; const firstNumber = Number(firstDigit); dfs(1, firstDigit, firstNumber); return result; };

github.com/muhammadk160...

"Never think that war, no matter how necessary, nor how justified, is not a crime." ~ Ernest Hemingway I wish for calmer heads to prevail.

No worries, we all get it.

If anything confusing requirements add to the realism. 🤣

export const longestCommonPrefix = (strings: string[]): string => { let prefix = strings[0] || ""; for (let i = 1; i < strings.length; i++) { while (strings[i]?.indexOf(prefix) !== 0) { prefix = prefix.slice(0, -1); if (prefix === "") return ""; } } return prefix; };

github.com/muhammadk160...

This is what I assumed, since the example function is being called "longestCommonPrefix".

export const compress = (characters: string[]): string[] => { const compressed: string[] = []; let currentChar = characters[0] as string; let count = 1; for (let i = 1; i <= characters.length; i++) { if (characters[i] === currentChar) { count++; } else { compressed.push(currentChar); if (count > 1) { compressed.push(count.toString()); } currentChar = characters[i] as string; count = 1; } } return compressed; };

github.com/muhammadk160...

List comprehensions 💜

export type TIngredient = { name: string; amount: number; }; export const calculateIngredients = ( ingredients: TIngredient[], targetServings: number, ): TIngredient[] => ingredients.map(ingredient => ({ ...ingredient, amount: ingredient.amount * targetServings, }));

github.com/muhammadk160...

const DIRECTIONS = [ [0, 1], [1, 0], [0, -1], [-1, 0], ] as const; export const largestPathSum = (grid: number[][]): number => { const rows = grid.length; if (!grid[0]) return 0; const cols = grid[0].length; let maxSum = 0; function dfs(x: number, y: number, visited: boolean[][], currentSum: number) { maxSum = Math.max(maxSum, currentSum); for (const [dx, dy] of DIRECTIONS) { const nx = x + dx; const ny = y + dy; if (!visited[nx] || !grid[nx]) continue; if (nx >= 0 && ny >= 0 && nx < rows && ny < cols && !visited[nx][ny]) { visited[nx][ny] = true; dfs(nx, ny, visited, currentSum + (grid[nx][ny] || 0)); visited[nx][ny] = false; } } } for (let i = 0; i < rows; i++) { for (let j = 0; j < cols; j++) { const visited = Array.from({ length: rows }, () => Array(cols).fill(false)); // @ts-ignore visited[i][j] = true; // @ts-ignore dfs(i, j, visited, grid[i][j]); } } return maxSum; };

I am starting to think that noUncheckedIndexedAccess rule is overkill.

github.com/muhammadk160...

const getLeylandNumbers = (n: number): number[] => { let count = n; let leylandNumbers: number[] = []; let x = 2; while (count > 0) { for (let i = 2; i <= x; i++) { leylandNumbers.push(Math.pow(i, x) + Math.pow(x, i)); } x++; count--; } return leylandNumbers.toSorted((a, b) => a - b).slice(0, n); };

github.com/muhammadk160...

No, you aren't wrong. That example is incorrect.

const getMinutes = (time: string): number => { const [hours, minutes] = time.split(":").map(Number); if (hours === undefined || minutes === undefined) throw new Error(`Invalid time format: ${time}`); return hours * 60 + minutes; }; export const findLongestTimeGap = (times: string[]): number => { let longestGap = 0; for (let i = 0; i < times.length - 1; i++) { const current = times[i] as string; const next = times[i + 1] as string; longestGap = Math.max(longestGap, getMinutes(next) - getMinutes(current)); } return longestGap; };

github.com/muhammadk160...

export const findLongestStreak = (values: boolean[]) => { let max = 0; for (let i = 0; i < values.length; i++) { let current = 0; while (values[i]) { current++; i++; } if (current > max) { max = current; } } return max; }

github.com/muhammadk160...

“Wait, not like that”: Free and open access in the age of generative AI The real threat isn’t AI using open knowledge — it’s AI companies killing the projects that make knowledge free

www.citationneeded.news/free-and-ope...

const SEMITONES = { C: 0, D: 2, E: 4, F: 5, G: 7, A: 9, B: 11, }; export const findLargestInterval = (keys: string[]): number => { const intervals = keys.map(key => { const note = key[0] as keyof typeof SEMITONES; const octave = Number(key[1]); return SEMITONES[note] + octave * 12; }); let largestInterval = 0; for (let i = 0; i < intervals.length - 1; i++) { const current = intervals[i] as number; const next = intervals[i + 1] as number; largestInterval = Math.max(largestInterval, Math.abs(current - next)); } return largestInterval; };

Thanks for forcing me to learn some basic Music Theory 😀

github.com/muhammadk160...

This has better documentation than half of the production code I write. 😆

Gorgeous.

export const calculatePrice = (closingDate: string, visitDate: string, price: number): number => { const closingDateTimestamp = new Date(closingDate).getTime(); const visitDateTimestamp = new Date(visitDate).getTime(); if (visitDateTimestamp > closingDateTimestamp) return price; const weeks = Math.floor( (closingDateTimestamp - visitDateTimestamp) / (1000 * 60 * 60 * 24 * 7), ); for (let i = 0; i < weeks; i++) { price -= price * 0.1; } return price; };

github.com/muhammadk160...

Skipped last week's problem since I felt like the solution I came up with wasn't mine. 😀