Two Sum: coding question

Problem

You get an array of integers nums and an integer target. Exactly two items in nums add up to target.

Return the indexes of these two items. You cannot use the same item two times. You can return the two indexes in any order.

Example 1

Input:: nums = [4,9,2,6], target = 8
Output:: [2,3]
Explanation:: nums[2] + nums[3] is 2 + 6, which is 8.

Example 2

Input:: nums = [5,1,5], target = 10
Output:: [0,2]
Explanation:: The two items with the value 5 are at indexes 0 and 2.

Example 3

Input:: nums = [-3,7,12], target = 4
Output:: [0,1]

Constraints

2 <= nums.length <= 10^4
-10^9 <= nums[i] <= 10^9
-10^9 <= target <= 10^9
Exactly one pair of items has the sum target.

Follow-up

Find a solution that runs in less than O(n^2) time.

SysRound wrote this statement. A reference solution checks every example.

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Amazon
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Reported Oct 6, 2025 · 1 source report
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Problem

You get an array of integers nums and an integer target. Exactly two items in nums add up to target.

Return the indexes of these two items. You cannot use the same item two times. You can return the two indexes in any order.

Example 1

Input:: nums = [4,9,2,6], target = 8
Output:: [2,3]
Explanation:: nums[2] + nums[3] is 2 + 6, which is 8.

Example 2

Input:: nums = [5,1,5], target = 10
Output:: [0,2]
Explanation:: The two items with the value 5 are at indexes 0 and 2.

Example 3

Input:: nums = [-3,7,12], target = 4
Output:: [0,1]

Constraints

2 <= nums.length <= 10^4
-10^9 <= nums[i] <= 10^9
-10^9 <= target <= 10^9
Exactly one pair of items has the sum target.

Follow-up

Find a solution that runs in less than O(n^2) time.

SysRound wrote this statement. A reference solution checks every example.

Two Sum

Problem

Example 1

Example 2

Example 3

Constraints

Follow-up

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Two Sum

Problem

Example 1

Example 2

Example 3

Constraints

Follow-up

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