BZOJ3781: 小B的询问

(A+1)2=A2+2A+1
裸的莫队

code：

#include<set>#include<map>#include<deque>#include<queue>#include<stack>#include<cmath>#include<ctime>#include<bitset>#include<string>#include<vector>#include<cstdio>#include<cstdlib>#include<cstring>#include<climits>#include<complex>#include<iostream>#include<algorithm>#define ll long long#define inf 1e8using namespace std;inline int read(){    char c; int x;    while(!((c=getchar())>='0'&&c<='9'));    x=c-'0';    while((c=getchar())>='0'&&c<='9') (x*=10)+=c-'0';    return x;}inline void up(int &x,const int &y){if(x<y)x=y;}inline void down(int &x,const int &y){if(x>y)x=y;}const int maxn = 51000;const int maxm = 51000; const int maxk = 51000;int a[maxn],n,m,K;struct node{    int l,r,i;    node(){}    node(const int &_l,const int &_r,const int &_i){l=_l;r=_r;i=_i;}}q[maxm];int N,id[maxn],L[maxn];inline bool cmp(const node &x,const node &y){return id[x.l]==id[y.l]?x.r<y.r:x.l<y.l;}ll s[maxk];ll ret[maxn];inline ll cal(const ll &x) {return 1|(x<<1);}void solve(){    int l=1,r=0;ll ans=0ll;    int pos=1;    for(int i=1;i<=id[n];++i)    {        while(pos<=m&&q[pos].l<L[i+1])        {            while(r<q[pos].r) ans+=cal(s[a[++r]]++);            while(l>q[pos].l) ans+=cal(s[a[--l]]++);            while(r>q[pos].r) ans-=cal(--s[a[r--]]);            while(l<q[pos].l) ans-=cal(--s[a[l++]]);            ret[q[pos++].i]=ans;        }    }}int main(){    n=read(),m=read(),K=read();    N=sqrt(n);    for(int i=1;i<=n;++i) id[i]=(i-1)/N+1; id[n+1]=id[n]+1;    for(int i=1;i<=id[n];++i) L[i]=(i-1)*N+1; L[id[n+1]]=n+1;    for(int i=1;i<=n;++i) a[i]=read();    for(int i=1;i<=m;++i)    {        int l=read(),r=read();        q[i]=node(l,r,i);    }    sort(q+1,q+m+1,cmp);    solve();    for(int i=1;i<=m;i++) printf("%lld\n",ret[i]);    return 0;}