import bisect from collections import * class BIT: def __init__(self,len_A): self.N = len_A + 10 self.bit = [0]*(len_A+10) # sum(A0 ~ Ai) # O(log N) def query(self,i): res = 0 idx = i+1 while idx: res += self.bit[idx] idx -= idx&(-idx) return res # Ai += x # O(log N) def update(self,i,x): idx = i+1 while idx < self.N: self.bit[idx] += x idx += idx&(-idx) # min_i satisfying {sum(A0 ~ Ai) >= w} (Ai >= 0) # O(log N) def lower_left(self,w): if (w < 0): return -1 x = 0 k = 1<<(self.N.bit_length()-1) while k > 0: if x+k < self.N and self.bit[x+k] < w: w -= self.bit[x+k] x += k k //= 2 return x class OrderBIT: def __init__(self,all_values,sort_flag = False): if sort_flag: self.A = all_values else: self.A = sorted(all_values) self.B = BIT(len(all_values)) self.num = 0 def insert_val(self,x,c=1): k = bisect.bisect_left(self.A,x) self.B.update(k,c) self.num += c def delete_val(self,x,c=1): k = bisect.bisect_left(self.A,x) self.B.update(k,-c) self.num -= c # find the k-th min_val (k:0-indexed) def find_kth_val(self,k): if self.num <= k: ##### MINIMUM VAL ####### return -10**9 return self.A[self.B.lower_left(k+1)] # count the number of values lower than or equal to x def count_lower(self,x): if x < self.A[0]: return 0 return self.B.query(bisect.bisect_right(self.A,x)-1) # min_val higher than x def find_higher(self,x): return self.find_kth_val(self.count_lower(x)) # min_val lower than x def find_lower(self,x): return self.find_kth_val(self.count_lower(x)-1) N = int(input()) A = list(map(int,input().split())) mod = 10**9 + 7 def segfunc(x, y): return (x+y)%mod ide_ele = 0 class SegTree: """ Segment Tree """ def __init__(self, init_val, segfunc, ide_ele): """ 初期化 init_val: 配列の初期値 """ n = len(init_val) self.segfunc = segfunc self.ide_ele = ide_ele self.num = 1 << (n - 1).bit_length() self.tree = [ide_ele] * 2 * self.num # 配列の値を葉にセット for i in range(n): self.tree[self.num + i] = init_val[i] # 構築していく for i in range(self.num - 1, 0, -1): self.tree[i] = segfunc(self.tree[2 * i], self.tree[2 * i + 1]) def update(self, k, x): """ k番目の値をxに更新 k: index(0-index) x: update value """ k += self.num self.tree[k] = x while k > 1: self.tree[k >> 1] = self.segfunc(self.tree[k], self.tree[k ^ 1]) k >>= 1 def query(self, l, r): """ [l, r)のsegfuncしたものを得る l: index(0-index) r: index(0-index) """ res = self.ide_ele l += self.num r += self.num while l < r: if l & 1: res = self.segfunc(res, self.tree[l]) l += 1 if r & 1: res = self.segfunc(res, self.tree[r - 1]) l >>= 1 r >>= 1 return res c = Counter(A) ans = 0 X = [(A[i],i) for i in range(N)] X.sort() cnd = [] U = SegTree([0 for _ in range(N)],segfunc,ide_ele) V = SegTree([0 for _ in range(N)],segfunc,ide_ele) for i in range(N): a,t = X[i] c[a] -= 1 cnd.append(t) if c[a]==0: for j in cnd: ans += U.query(j+1,N)*V.query(0,j) ans %= mod for j in cnd: U.update(j,pow(2,N-1-j,mod)) V.update(j,pow(2,j,mod)) cnd = [] U = SegTree([0 for _ in range(N)],segfunc,ide_ele) V = SegTree([0 for _ in range(N)],segfunc,ide_ele) c = Counter(A) for i in range(N-1,-1,-1): a,t = X[i] c[a] -= 1 cnd.append(t) if c[a]==0: for j in cnd: ans += U.query(j+1,N)*V.query(0,j) ans %= mod for j in cnd: U.update(j,pow(2,N-1-j,mod)) V.update(j,pow(2,j,mod)) cnd = [] print(ans)