注:WA的数据
```
2
5 6
```
正确输出:
`0`
程序输出:
`2`
by 一只大龙猫 @ 2021-09-11 17:07:10
@[滑蒻稽](/user/113181) 仍然WA
by 一只大龙猫 @ 2021-09-11 17:10:04
@[一只大龙猫](/user/511907) 哪道题
by Cht_master @ 2021-09-11 17:10:41
```cpp
void work(){
for(long long i=1;i<=n;i++){
ans+=i-sum(a[i]-1)-1;
add(a[i],1);
}
cout<<ans;
return;
}
```
by 滑蒻稽 @ 2021-09-11 17:10:55
@[滑蒻稽](/user/113181) 谢谢!
by 一只大龙猫 @ 2021-09-11 21:21:44