3809: Gty的二逼妹子序列 莫队算法+分块

这题还卡树状数组！@#￥%……

#include<cstdio>#include<cstdlib>#include<cstring>#include<cmath>#include<iostream>#include<algorithm>#include<queue>#include<vector>#include<set>#include<map>#define lowbit(x) (x&(-x))using namespace std;int sc(){    int i=0;char c=getchar();    while(c>'9'||c<'0')c=getchar();    while(c>='0'&&c<='9')i=i*10+c-'0',c=getchar();    return i;}struct W{int l,r,a,b,pos;}q[1000001];int a[100010],bl[100010],cnt[100010];int block_ans[100100];int ans[1000010],n,m,block;bool cmp(W a,W b){    return bl[a.l]==bl[b.l]?a.r<b.r:bl[a.l]<bl[b.l];}int query(int l,int r){    int x=bl[l],y=bl[r],ans=0;    if(x==y)    {        for(int i=l;i<=r;i++)ans+=(bool)cnt[i];        return ans;    }    for(int i=x+1;i<y;i++)ans+=block_ans[i];    for(int i=l;bl[i]==x;i++)ans+=(bool)cnt[i];    for(int i=r;bl[i]==y;i--)ans+=(bool)cnt[i];    return ans;}void cal(int x,int f){    cnt[x]+=f;    if(f==1&&cnt[x]==1)        block_ans[bl[x]]++;    else if(f==-1&&cnt[x]==0)        block_ans[bl[x]]--;}void print(int x){    if(x==0){puts("0");return;}    char c[20]; int i=0;    while(x)c[++i]=x%10+'0',x/=10;    while(i)putchar(c[i--]);    puts("");}int main(){    n=sc(),m=sc();block=sqrt(n);    for(int i=1;i<=n;i++)a[i]=sc();    for(int i=1;i<=m;i++)q[i]=(W){sc(),sc(),sc(),sc(),i};    for(int i=1;i<=n;i++)bl[i]=(i-1)/block+1;    sort(q+1,q+m+1,cmp);    int l=q[1].l,r=q[1].l;    cal(a[q[1].l],1);    for(int i=1;i<=m;i++)    {        while(l<q[i].l)cal(a[l++],-1);        while(r>q[i].r)cal(a[r--],-1);        while(l>q[i].l)cal(a[--l],1);        while(r<q[i].r)cal(a[++r],1);        ans[q[i].pos]=query(q[i].a,q[i].b);    }    for(int i=1;i<=m;i++)print(ans[i]);    return 0;}