Adding the adjacent difference modulus values of removed element . Removing adjacent difference modulus value after removing element
$ temp = abs ( $ arr [ $ i ] - $ arr [ $ i + 1 ] ) + abs ( $ arr [ $ i ] - $ arr [ $ i - 1 ] ) - abs ( $ arr [ $ i - 1 ] - $ arr [ $ i + 1 ] ) ; } else if ( $ i == 0 ) { $ value = $ value + abs ( $ arr [ $ i ] - $ arr [ $ i + 1 ] ) ; $ temp = abs ( $ arr [ $ i ] - $ arr [ $ i + 1 ] ) ; } else $ temp = abs ( $ arr [ $ i ] - $ arr [ $ i - 1 ] ) ; $ maximum = max ( $ maximum , $ temp ) ; }