Find Missing And Repeated Values

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Find Missing And Repeated Values

Find the one value that appears twice and the one value that is missing from an $n \times n$ grid containing numbers from $1 $to$ n^2$.

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Problem Statement

You are given an $n \times n$ matrix containing integers from $1 $to$ n^2$.

Exactly one number appears twice, and exactly one number in the range $1 $to$ n^2$ does not appear at all.

Return the repeated value and the missing value.

Notes

The matrix contains $n^2$ cells.
Every value should be in the range $1 $to$ n^2$.
There is guaranteed to be exactly one repeated value and exactly one missing value.

Input Format

A 2D integer array grid of size $n \times n$ .
Each cell contains an integer in the range $[1, n^2]$ .
One value appears twice, one value is absent.

Output Format

Return an array of two integers [repeated, missing].

Constraints

$1 \le n \le 50$ (typical interview-scale formulation)
Values are in $[1, n^2]$
Exactly one value is repeated and exactly one value is missing

Examples

Sample cases returned by the problem API.

Example 1

Input

grid = [[1,3],[2,2]]

Output

[2,4]

Explanation

The values should be 1, 2, 3, 4. The number 2 appears twice, and 4 is missing.

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