Two Sum

EasyArrays & Hashing

Given an array of integers nums and an integer target, return the indices of the two numbers that add up to target.

You may assume that each input has exactly one solution, and you may not use the same element twice. Return the answer as [i, j] with i < j.

Example

nums = [2, 7, 11, 15], target = 9
=> [0, 1]   // nums[0] + nums[1] == 9

Implement

function TwoSum(nums: int[], target: int) -> int[]

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BAML docs

baml describe

Search the BAML stdlib (260 symbols). Try a type, function, or method name.

let x = 0;

mutable binding

let nums: int[] = [];

typed binding

function Add(a: int, b: int) -> int {
  return a + b;
}

if (x > 0) {
  ...
} else {
  ...
}

while (i < n) {
  i += 1;
}

for (x in nums) {
  ...
}

iterate values

break;   continue;   return v;

nums.length()

nums[i]

read (0-indexed)

nums[i] = v

write

nums.push(x)

nums.pop()

returns T? (optional)

nums.slice(a, b)   nums.reverse()

nums.sort_by_key(k)   nums.sort_by(cmp)

returns a sorted copy (no bare .sort())

let m: map<string, int> = {};

m.set("a", 1);

m.get("a")

returns int? (null if absent)

m.has("a")   m.keys()

m.set(n.to_string(), true);

int keys are unsupported: convert to string

s.length()

number of characters

s.char_at(i)   s.substring(a, b)

s.split(",")   s.to_lower_case()

c.is_alphanumeric()   c == "a"

a / b

integer division

a % b

remainder

x.abs()   x.pow(e)   x.min(y)   x.max(y)

x & 1   x >> 1   x << 2   x ^ y

bitwise ops

n.to_string()

value to string

int.parse(s)

string to int

let node: ListNode? = null;

if (x == null) {
  return 0;
}
// x is non-null below

guard-and-return narrows the type

class ListNode {
  val int
  next ListNode?
}

ListNode { val: 1, next: null }

construct with { }

node.val   node.next