o ( open bracket ) stores count of ' ( ' and c ( close bracket ) stores count of ' ) '
var o = 0 , c = 0 ; for ( var i = 0 ; i < s . length ; i ++ ) { if ( s [ i ] == ' ' ) o ++ ; if ( s [ i ] == ' ' ) c ++ ; } if ( o != c ) return - 1 ; var a = new Array ( s . Length ) ; if ( s [ 0 ] == ' ' ) a [ 0 ] = 1 ; else a [ 0 ] = - 1 ; if ( a [ 0 ] < 0 ) ans += Math . abs ( a [ 0 ] ) ; for ( var i = 1 ; i < s . length ; i ++ ) { if ( s [ i ] == ' ' ) a [ i ] = a [ i - 1 ] + 1 ; else a [ i ] = a [ i - 1 ] - 1 ; if ( a [ i ] < 0 ) ans += Math . abs ( a [ i ] ) ; } return ans ; }