Else find the length .
int arr [ MAX ] = { 0 } ; for ( int i = 0 ; i < n ; i ++ ) arr [ i ] = ( s [ i ] == '0' ? 1 : -1 ) ; int dp [ MAX ] [ 3 ] ; memset ( dp , -1 , sizeof dp ) ; return findlength ( arr , s , n , 0 , 0 , dp ) ; }