if satisfies the second case
else if ( i == j ) ans += h [ i ] * ( h [ i ] - 1 ) * h [ rem ] / 2 ; else if ( i == rem ) ans += h [ i ] * ( h [ i ] - 1 ) * h [ j ] / 2 ; else if ( rem == j ) ans += h [ j ] * ( h [ j ] - 1 ) * h [ i ] / 2 ;