Loop to find the maximum and minimum adjacent element to missing number
for ( let i = 0 ; i < n ; i ++ ) { if ( i > 0 && arr [ i ] == - 1 && arr [ i - 1 ] != - 1 ) { mn = Math . min ( mn , arr [ i - 1 ] ) ; mx = Math . max ( mx , arr [ i - 1 ] ) ; } if ( i < ( n - 1 ) && arr [ i ] == - 1 && arr [ i + 1 ] != - 1 ) { mn = Math . min ( mn , arr [ i + 1 ] ) ; mx = Math . max ( mx , arr [ i + 1 ] ) ; } } let res = ( mx + mn ) / 2 ; return res ; }