LeetCode: Search a 2D Matrix Solution

Approach

Flatten 2D into 1D array and do binary search

Implementation

1const binarySearch = (arr, target) => {
2  let n = arr.length
3  let [begin, end] = [0, n - 1]
4  let res = -1
5
6  while (begin <= end) {
7    let mid = Math.floor((begin + end) / 2)
8
9    if (arr[mid] > target) {
10      end = mid - 1
11    } else if (arr[mid] < target) {
12      begin = mid + 1
13    } else {
14      res = mid
15      break
16    }
17  }
18
19  return res
20}
21
22var searchMatrix = function (matrix, target) {
23  const arr = matrix.flat()
24
25  return binarySearch(arr, target) === -1 ? false : true
26}

References

Original problem

Similar problems

Search a 2D Matrix II