# [Solution] Build a Matrix With Conditions solution leetcode

## Build a Matrix With Conditions solution leetcode

Build a Matrix With Conditions solution leetcode – You are given a positive integer `k`. You are also given:

• a 2D integer array `rowConditions` of size `n` where `rowConditions[i] = [abovei, belowi]`, and
• a 2D integer array `colConditions` of size `m` where `colConditions[i] = [lefti, righti]`.

The two arrays contain integers from `1` to `k`.

You have to build a `k x k` matrix that contains each of the numbers from `1` to `k` exactly once. The remaining cells should have the value `0`.

## Build a Matrix With Conditions solution leetcode

The matrix should also satisfy the following conditions:

• The number `abovei` should appear in a row that is strictly above the row at which the number `belowi` appears for all `i` from `0` to `n - 1`.
• The number `lefti` should appear in a column that is strictly left of the column at which the number `righti` appears for all `i` from `0` to `m - 1`.

Return any matrix that satisfies the conditions. If no answer exists, return an empty matrix.

Example 1: ```Input: k = 3, rowConditions = [[1,2],[3,2]], colConditions = [[2,1],[3,2]]
Output: [[3,0,0],[0,0,1],[0,2,0]]
Explanation: The diagram above shows a valid example of a matrix that satisfies all the conditions.
The row conditions are the following:
- Number 1 is in row 1, and number 2 is in row 2, so 1 is above 2 in the matrix.
- Number 3 is in row 0, and number 2 is in row 2, so 3 is above 2 in the matrix.
The column conditions are the following:
- Number 2 is in column 1, and number 1 is in column 2, so 2 is left of 1 in the matrix.
- Number 3 is in column 0, and number 2 is in column 1, so 3 is left of 2 in the matrix.
Note that there may be multiple correct answers.
```

## Build a Matrix With Conditions solution leetcode

```Input: k = 3, rowConditions = [[1,2],[2,3],[3,1],[2,3]], colConditions = [[2,1]]
Output: []
Explanation: From the first two conditions, 3 has to be below 1 but the third conditions needs 3 to be above 1 to be satisfied.
No matrix can satisfy all the conditions, so we return the empty matrix.
```

## Build a Matrix With Conditions solution leetcode

• `2 <= k <= 400`
• `1 <= rowConditions.length, colConditions.length <= 104`
• `rowConditions[i].length == colConditions[i].length == 2`
• `1 <= abovei, belowi, lefti, righti <= k`
• `abovei != belowi`
• `lefti != righti`