text: # Problem There are n points on a coordinate axis OX.The i-th point is located at the integer point x_i and has a speed v_i.It is guaranteed that no two points occupy the same coordinate.All n points move with the constant speed, the coordinate of the i-th point at the moment t (t can be non-integer) is calculated as x_i + t ⋅ v_i.Consider two points i and j.Let d(i, j) be the minimum possible distance between these two points over any possible moments of time (even non-integer).It means that if two points i and j coincide at some moment, the value d(i, j) will be 0.Your task is to calculate the value ∑_{1 ≤ i < j ≤ n} d(i, j) (the sum of minimum distances over all pairs of points).Input The first line of the input contains one integer n (2 ≤ n ≤ 2 ⋅ 10^5) — the number of points.The second line of the input contains n integers x_1, x_2, ..., x_n (1 ≤ x_i ≤ 10^8), where x_i is the initial coordinate of the i-th point.It is guaranteed that all x_i are distinct.The third line of the input contains n integers v_1, v_2, ..., v_n (-10^8 ≤ v_i ≤ 10^8), where v_i is the speed of the i-th point.Output Print one integer — the value ∑_{1 ≤ i < j ≤ n} d(i, j) (the sum of minimum distances over all pairs of points).Examples Input 3 1 3 2 -100 2 3 Output 3 Input 5 2 1 4 3 5 2 2 2 3 4 Output 19 Input 2 2 1 -3 0 Output 0 # Solution import bisect def getsum(tree , i): s = 0 i += 1 while i>0: s += tree[i] i -= i & (-i) return s def updatebit(tree , n , i , v): i+= 1 while i <= n: tree[i] += v i += i & (-i) n = int(input()) x = list(map(int , input().split())) v = list(map(int , input().split())) p = [[x[i] , v[i]] for i in range(len(x))] vs = sorted(list(set(v))) p = sorted(p , key = lambda i : i[0]) l = len(vs) cnt = [0]*(l+1) xs = [0]*(l+1) ans = 0 for pnt in p: pos = bisect.bisect_left(vs , pnt[1]) ans += getsum(cnt , pos) * pnt[0] - getsum(xs , pos) updatebit(cnt , l , pos , 1) updatebit(xs , l , pos , pnt[0]) print(ans)