58 lines
982 B
C++
58 lines
982 B
C++
#include<iostream>
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#include<string.h>
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using namespace std;
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__int64 a[100005],c[100005],d[100005],n;
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int lowbit(int x)
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{
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return x&(-x);
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}
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__int64 sumc(int x)
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{
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__int64 s=0;
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while(x>0)
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{
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s+=c[x];
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x-=lowbit(x);
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}
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return s;
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}
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__int64 sumd(int x)
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{
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__int64 s=0;
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while(x>0)
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{
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s+=d[x];
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x-=lowbit(x);
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}
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return s;
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}
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void updata(int i,int j)
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{
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while(i<=n)
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{
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c[i]+=1;
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d[i]+=j;
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i+=lowbit(i);
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}
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}
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int main()
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{
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while(scanf("%I64d",&n)>0)
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{
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memset(a,0,sizeof(a));
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memset(c,0,sizeof(c));
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memset(d,0,sizeof(d));
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__int64 s=0,count=0;
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for(int i=1;i<=n;i++)
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{
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scanf("%d",&a[i]);
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updata(a[i],a[i]);
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count+=a[i];
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s+=(i-sumc(a[i]))*a[i];
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s+=count-sumd(a[i]);
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}
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printf("%I64d\n",s);
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}
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return 0;
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}
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