268. Отсутствующее число (Easy) (https://leetcode.com/problems/missing-number/)
Дан массив nums, содержащий n различных чисел в диапазоне [0, n], верните единственное число из этого диапазона, которое отсутствует в массиве. Ограничения: n == nums.length 1 <= n <= 10^4 0 <= nums[i] <= n Все числа в nums уникальны. Дополнительно: сможете ли вы реализовать решение, используя только O(1) дополнительной памяти и O(n) времени выполнения?
function missingNumber(nums: number[]): number {
const n = nums.length
const expectedSum = (n * (n + 1)) / 2
const actualSum = nums.reduce((acc, num) => acc + num, 0)
return expectedSum - actualSum
}
// Local check:
console.log(missingNumber([3, 0, 1]))
console.log(missingNumber([0, 1]))
console.log(missingNumber([9, 6, 4, 2, 3, 5, 7, 0, 1]))Example 1:
Input: nums = [3,0,1]
Output: 2
Explanation: n = 3 since there are 3 numbers, so all numbers are in the range [0,3].
2 is the missing number in the range since it does not appear in nums.
Example 2:
Input: nums = [0,1]
Output: 2
Explanation: n = 2 since there are 2 numbers, so all numbers are in the range [0,2].
2 is the missing number in the range since it does not appear in nums.
Example 3:
Input: nums = [9,6,4,2,3,5,7,0,1]
Output: 8
Explanation: n = 9 since there are 9 numbers, so all numbers are in the range [0,9].
8 is the missing number in the range since it does not appear in nums.150-evaluate-reverse-polish-notation 283-move-zeroes 217 — то же set-семейство leetcode