text: Count Negative Numbers in a Column | Function to count negative number ; initialize result ; Start with top right corner ; Follow the path shown using arrows above ; j is the index of the last negative number in this row . So there must be ( j + 1 ) ; negative numbers in this row . ; move to the left and see if we can find a negative number there ;
code: function countNegative ( M , n , m ) { let count = 0 ; let i = 0 ; let j = m - 1 ; while ( j >= 0 && i < n ) { if ( M [ i ] [ j ] < 0 ) { count += j + 1 ; i += 1 ; } else j -= 1 ; } return count ; } ` let M = [ [ - 3 , - 2 , - 1 , 1 ] , [ - 2 , 2 , 3 , 4 ] , [ 4 , 5 , 7 , 8 ] ] ; document . write ( countNegative ( M , 3 , 4 ) ) ;