兔子的逆序对----树状数组+数学推导

#include
#include
#include
#include
using namespace std;
//#define int long long
const int N = 100010;
int tr[N];
int n,m;
int lowbit(int x)
{
    return x&-x;
}
void add(int x,int v)
{
    for(int i=x;i<=n;i+=lowbit(i))tr[i]+=v;
}
int query(int x)
{
    int res=0;
    for(int i=x;i;i-=lowbit(i))res+=tr[i];
    return res;
}
signed main()
{
    cin>>n;
    int res=0;
    for(int i=1;i<=n;i++)
    {
        int x;scanf("%d",&x);
        res+=query(n)-query(x);
        add(x,1);
    }
    res=res&1;
    cin>>m;
    while(m--)
    {
        int l,r;
        scanf("%d%d",&l,&r);
        int t=(r-l)*(r-l+1)>>1;
        res^=t&1;
        if(res)printf("disliken");
        else printf("liken");
    }
}