bzoj3289 树状数组加莫队注意这题每天的交换该是不影响的。。。还有一次交换等价于去掉一个逆序

#include<iostream>#include<cstdio>#include<cstring>#include<cstdlib>#include<map>#include<ctime>#include<vector>#include<set>#include<cmath>#include<algorithm>#define inf 1000000000#define ll long long#define eps 1e-5using namespace std;int read(){int x=0,f=1;char ch=getchar();while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}return x*f;}unsigned int now,ans[50005];int n,m;int a[50005],disc[50005],belong[50005];int t[50005];struct query{int l,r,id;}q[50005];bool operator<(query a,query b){if(belong[a.l]==belong[b.l])return a.r<b.r;return belong[a.l]<belong[b.l];}void add(int x,int val){for(int i=x;i<=n;i+=i&-i)t[i]+=val;}unsigned int query(int x){unsigned int sum=0;for(int i=x;i;i-=i&-i)sum+=t[i];return sum;}void solve(){sort(q+1,q+m+1);int l=1,r=0;for(int i=1;i<=m;i++){while(l<q[i].l)add(a[l],-1),now-=query(a[l]-1),l++;while(r>q[i].r)add(a[r],-1),now-=r-l-query(a[r]),r--;while(l>q[i].l)l--,add(a[l],1),now+=query(a[l]-1);while(r<q[i].r)r++,add(a[r],1),now+=r-l+1-query(a[r]);ans[q[i].id]=now;}}int main(){n=read();int t=sqrt(n);for(int i=1;i<=n;i++)disc[i]=a[i]=read();sort(disc+1,disc+n+1);for(int i=1;i<=n;i++)a[i]=lower_bound(disc+1,disc+n+1,a[i])-disc;m=read();for(int i=1;i<=m;i++)q[i].l=read(),q[i].r=read(),q[i].id=i;for(int i=1;i<=m;i++)belong[i]=(i-1)/t+1;solve();for(int i=1;i<=m;i++)printf("%d\n",ans[i]);return 0;}