Two Pieces Glued Into a Code

Medium

You are given a list of digit strings pieces and a digit string target. Count the ordered index pairs (i, j) with i ≠ j such that pieces[i] followed by pieces[j] is exactly target. The pairs (i, j) and (j, i) count as different.

Example 1

pieces=["12", "3412", "1234", "12"], target="123412" → 4

Pairs (0, 1) and (3, 1) work: "12" + "3412". Pair (2, 0) also gives "123412" as "1234" + "12", and so does (2, 3). That is 4 in total.

Example 2

pieces=["5", "5"], target="55" → 2

Pairs (0, 1) and (1, 0) count separately, even though they glue identical strings.

Example 3

pieces=["7", "8", "9"], target="98" → 1

Constraints

2 ≤ len(pieces) ≤ 100
1 ≤ len(pieces[i]) ≤ 100
2 ≤ len(target) ≤ 100
All strings consist of digits and have no leading zeros

Have you seen this problem in a real interview?

Solved by0

Tried by0

Submissions0

Acceptance—

Topics

Array Hash Table String Counting

Similar problems

Most Searched Words Medium Domain Visit Rollup Medium Ranking Finalists by Jury Ballots Medium Palindrome From Two-Letter Cards Medium Most Talkative Sender Medium

Input

pieces=["12", "3412", "1234", "12"], target="123412"

Expected

Run checks the first 3 tests in your browser. Submit checks all 112 tests on the server, hidden ones included.