全部RE，可是对样例了啊QwQ，本蒟蒻要崩溃了，求各位大佬帮助

#include<iostream>
#define int long long
using namespace std;
int a[500005],b[500005],ans,n;
int lowbit(int x) {return (x&(-x));}
void upload(int p) {for(int i=p;i<=500005; i+=lowbit(i))a[i]++;}
int getsum(int x) {
    int sum=0;
    for(int i=x; i; i-=lowbit(i))sum+=a[i];
    return sum;
}
signed main() {
    scanf("%lld",&n);
    for(int i=1; i<=n; i++) scanf("%lld",&b[i]);
    for(int i=1; i<=n; i++) {
        upload(b[i]);
        ans+=i-getsum(b[i]);
    }
    printf("%lld",ans);
}