gjas06 @ 2019-08-10 19:57:59

by gjas06 @ 2019-08-10 20:03:17

附上代码```cpp

include<bits/stdc++.h>

using namespace std;

long long x[500010],y[500010],z[500010],n,a,b=0,t=0; int lowbit(int x) { return x&-x; } bool cmp(int a,int b) { return x[a]>x[b]; } void build(int a) { int i; for(i=a;i<=n;i+=lowbit(i)) z[i]++; } long long sum(int a) { long long i,b=0; for(i=a;i>0;i-=lowbit(i)) b+=z[i]; return b; }

```c
#include<bits/stdc++.h>
using namespace std;

long long x[500010],y[500010],z[500010],n,a,b=0,t=0;
int lowbit(int x)
{
    return x&-x;
}
bool cmp(int a,int b)
{
    return x[a]>x[b];
}
void build(int a)
{
    int i;
    for(i=a;i<=n;i+=lowbit(i))
    z[i]++;
}
long long sum(int a)
{
    long long i,b=0;
    for(i=a;i>0;i-=lowbit(i))
    b+=z[i];
    return b;
}

by gjas06 @ 2019-08-10 20:03:39

int main()
{
    cin>>n;
    for(a=1;a<=n;a++)
    { cin>>x[a]; y[a]=a; }
    sort(y+1,y+n+1,cmp);
    for(a=1;a<=n;a++)
    {
        if(x[y[a]]==x[y[a+1]]) t++;
        else
        {

        b-=(1+t)*t/2;
        t=0;
         }
        b+=sum(y[a]);
        build(y[a]);
    }
    cout<<b;
    return 0;
}

by gjas06 @ 2019-08-11 16:46:30

叫了10几次，终于过了

by gjas06 @ 2019-08-11 16:47:13

初始化应该将相同的数根据坐标从大到小排

by gjas06 @ 2019-08-11 16:56:49

cmp改为return x[a]>x[b]||x[a]==x[b]&&a>b;

by PAN_盼达明 @ 2019-08-29 20:02:16

暖？