Find the first matching pair

Goal

Fill in FindPair so it searches every pair i, j from 1 to Limit and returns the first pair whose product equals Target, written as "i,j", or "none" if there is no such pair.

Example

Limit = 5
Target = 6
fmt.Println(FindPair()) // 2,3

Target = 7
fmt.Println(FindPair()) // none

Pairs are checked in row-major order: i is the row (outer loop) and j is the column (inner loop), so 1,1 1,2 1,3 ... then 2,1 2,2 ... With Limit = 6 and Target = 6, both 1,6 and 2,3 match, and 1,6 wins because it comes first.

• Target = 1 with Limit of 1 or more gives "1,1".
• A prime Target bigger than Limit has no pair, except the pair with 1 that fits inside the limit: Limit = 7, Target = 7 gives "1,7", but Limit = 5, Target = 7 gives "none".
• If Limit is 0 or negative, nothing is searched and the answer is "none".

Rules

• Edit pair.go. The function has a // TODO comment and a return line you will change.
• Limit and Target are variables outside the function. The tests give them different values, so read them each time the function runs.
• Use one loop nested inside another, with i outside and j inside, both counting from 1 to Limit.
• Keep a found flag (a bool declared before the loops) and stop both loops with break as soon as a pair is found. A break only leaves the loop it is written in, so the outer loop needs its own check of the flag.
• Do not return from inside the loops: finish the loops, then return the result.
• Do not change the lines var Limit int, var Target int or func FindPair() string {. Do not add imports other than fmt.

What you'll practice

Nested loops, stopping both loops with break and a flag, and building a result with fmt.Sprintf.

Run it

gonomicon fetch week-1/11-08-first-matching-pair
cd 11-08-first-matching-pair
gonomicon test
gonomicon submit

Hints

1. Use two loops, i outside and j inside, both from 1 up to Limit. Check i*j == Target on every pass of the inner loop.
2. Declare found := false and a result string before the loops. When you hit a match, store the pair, set found = true and break. A break only leaves the inner loop, so add if found { break } right after the inner loop in the outer one.
3. Start with result := "none". When i*j == Target, set result = fmt.Sprintf("%d,%d", i, j), set found = true and break. After the inner loop, if found { break }. Return result after the loops.