【JZOJ 5260】 区间第k小

分块

既然有某只Alan_cty写了，我又写不过他=w=就不写了

#include<cmath>#include<cstdio>#include<cstring>#include<algorithm>#define fo(i,a,b) for(int i=a;i<=b;i++)#define fd(i,b,a) for(int i=b;i>=a;i--)#define max(x,y) ((x)>(y)?(x):(y))#define min(x,y) ((x)<(y)?(x):(y))#define mset(a,x) memset(a,x,sizeof(a))using namespace std;typedef long long ll;char ch;void read(int &n){    n=0;    for(ch=getchar();ch<'0' || ch>'9';ch=getchar());    for(;'0'<=ch && ch<='9';ch=getchar()) n=n*10+ch-'0';}const int N=1e5+5,M=320;int n,m,zm,w,a[N],f[M][M][M],cnt[M][N],F[M],G[N];bool bz[N];int getnum(int x,int y,int z){    return x>y?0:cnt[y][z]-cnt[x-1][z];}void add(int x,int y,int i){    int t=++G[a[i]]+getnum(x+1,y-1,a[i]);    if(t>w+1) bz[a[i]]=1;    if(bz[a[i]]) return;    if(t==w+1) bz[a[i]]=1,F[a[i]/zm]-=w;    else F[a[i]/zm]++;}int main(){    freopen("kth.in","r",stdin);    freopen("kth.out","w",stdout);    int Q,type,l,r,x,y,k,mx=0,ans=0;    read(n),read(w),read(Q),read(type);m=sqrt(n);if(n/m>m) m++;    fo(i,1,n)    {        read(a[i]),mx=max(mx,a[i]);        cnt[i/m][a[i]]++;    }    zm=sqrt(mx);if(mx/zm>zm) zm++;    fo(l,0,m)    {        mset(G,0);mset(bz,0);        fo(r,l,m)        {            fo(k,0,zm) f[l][r][k]=f[l][r-1][k];            fo(i,max(1,r*m),min(n,r*m+m-1))            {                if(bz[a[i]]) continue;                if(++G[a[i]]==w+1) bz[a[i]]=1,f[l][r][a[i]/zm]-=w;                else f[l][r][a[i]/zm]++;            }        }    }    mset(G,0);    fo(i,1,m)        fo(j,0,n) cnt[i][j]+=cnt[i-1][j];    while(Q--)    {        read(l),read(r),read(k);l^=type*ans,r^=type*ans,k^=type*ans;        x=l/m,y=r/m;        mset(F,0);        fo(i,0,zm) F[i]=f[x+1][y-1][i];        if(x==y) fo(i,l,r) add(x,y,i);        else        {            fo(i,l,min(n,x*m+m-1)) add(x,y,i);            fo(i,max(1,y*m),r) add(x,y,i);        }        ans=n;        for(int i=0;i<=zm;i++)            if(k<=F[i])            {                fo(j,i*zm,i*zm+zm-1)                {                    int t=G[j]+getnum(x+1,y-1,j);                    if(t>w) continue;                    if(k<=t) {ans=j;break;}                    else k-=t;                }                break;            }            else k-=F[i];        printf("%d\n",ans);        if(x==y) fo(i,l,r) G[a[i]]=bz[a[i]]=0;        else        {            fo(i,l,min(n,x*m+m-1)) G[a[i]]=bz[a[i]]=0;            fo(i,max(1,y*m),r) G[a[i]]=bz[a[i]]=0;        }    }    return 0;}

二维数据结构

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