Query a Header-Encoded Matrix
NVIDIA● EasyFULLTIMEOAProblem statement
The first value of arr gives the number of columns in a matrix. The remaining values list its cells row by row, from left to right.
For each query [r,c], return the cell at row r, column c. Rows and columns start at 1. Return the answers in query order. An empty query list returns an empty array.
Function
matrixQueries(arr: int[], queries: int[][]) → int[]Examples
Example 1
arr = [3,10,20,30,40,50,60,70,80,90]queries = [[1,1],[3,2],[2,3]]return = [10,80,60]The header 3 describes three columns. The matrix rows are [10,20,30], [40,50,60], and [70,80,90]. The requested cells contain 10, 80, and 60 in that order.
Example 2
arr = [1,-7,0,12]queries = [[3,1],[1,1],[3,1]]return = [12,-7,12]There is one column. Queries may repeat or arrive in any row order; return the value for each query in its original position.
Constraints
- 2 <= arr.length <= 200001.
- Every value in arr is between -10^9 and 10^9.
- arr[0] is a column count between 1 and 200000; the remaining values form at least one complete row.
- 0 <= queries.length <= 200000.
- Every query has exactly two positive integers, each at most 200000.
- Every query [r,c] names an existing cell using one-based row and column indices.