Set Matrix Zeroes

/** Do not return anything, modify matrix in-place instead. */
export function setZeroes(matrix: number[][]): void {
  const [m, n] = [matrix.length, matrix[0].length];
 
  let firstColHasZero = false;
  let firstRowHasZero = false;
  for (let i = 0; i < m; i++) {
    for (let j = 0; j < n; j++) {
      if (matrix[i][j] === 0) {
        matrix[i][0] = 0;
        matrix[0][j] = 0;
        firstColHasZero ||= j === 0;
        firstRowHasZero ||= i === 0;
      }
    }
  }
 
  for (let i = 1; i < m; i++) {
    for (let j = 1; j < n; j++) {
      if (matrix[i][0] === 0 || matrix[0][j] === 0) {
        matrix[i][j] = 0;
      }
    }
  }
 
  if (firstColHasZero) {
    for (let i = 0; i < m; i++) {
      matrix[i][0] = 0;
    }
  }
 
  if (firstRowHasZero) {
    for (let j = 0; j < n; j++) {
      matrix[0][j] = 0;
    }
  }
}