Given an array x of size n > 3 and an integer N, return the indices of three elements in the array that sum up to the given integer N. If there is no such triplet, return -1.
For example, given x = [1 4 2 5 8 10] and N = 17, the function should return [2 4 5] because x(2) + x(4) + x(5) = 4 + 5 + 8 = 17. With the same x but N = 24, the function should return -1 because there is no triplet whose sum equals 24.
Note that the list of three indices is not necessarily unique. For example, given x = [1 2 3 4 5 6] and N = 9, the expected output can be either [1 2 6] or [1 3 5] since x(1) + x(2) + x(6) = 1 + 2 + 6 = 9 and x(1) + x(3) + x(5) = 1 + 3 + 5 = 9. The tests simply verify that the sum of the elements at the found indices is correct.
Solve

Solution Stats

27 Solutions

15 Solvers

Last Solution submitted on Oct 14, 2026

Last 200 Solutions

Problem Comments

Solution Comments

Show comments

Problem Recent Solvers15

Chris Cleveland goc3 Anne Adamczyk Alexander Ross

Suggested Problems

More from this Author53

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!