Submission #3725421

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Source Code Expand

class BIT():
    def __init__(self,number):
        self.n=number
        self.list=[0]*(number+1)
        
    def add(self,i,x):#ith added x  1indexed
        while i<=self.n:
            self.list[i]+=x
            i+=i&-i
            
    def search(self,i):#1-i sum
        s=0
        while i>0:
            s+=self.list[i]
            i-=i&-i
        return s
    
    def suma(self,i,j):#i,i+1,..j sum
        return self.search(j)-self.search(i-1)
N=int(input())
A=[int(i) for i in input().split()]
import sys
tree=BIT(N)
dd={}
for i in range(N):
    if dd.get(A[i],-1)!=-1:
        print(-1)
        sys.exit()
    dd[A[i]]=i
B=sorted(A)
ans=0
for i in range(N-1,-1,-1):
    s=dd[B[i]]
    t=tree.search(s+1)
    ans+=B[i]*t
    tree.add(s+1,1)
print(ans)

Submission Info

Judge Result