1. 程式人生 > >【CDQ分治】BZOJ2683 簡單題

【CDQ分治】BZOJ2683 簡單題

題面在這裡

把每個詢問操作Q分為4個(容斥)

然後對於每個Q,要求出tA<tQ,xAxQ,yAyQwA之和

直接CDQ分治就好了

示例程式:

#include<cstdio>
#include<algorithm>
using namespace std;
typedef long long ll;
inline char nc(){
    static char buf[100000],*p1=buf,*p2=buf;
    return p1==p2&&(p2=(p1=buf)+fread(buf,1,100000,stdin),p1==p2)?EOF:*p1++;
}
inline
int red(){ int res=0,f=1;char ch=nc(); while (ch<'0'||'9'<ch) {if (ch=='-') f=-f;ch=nc();} while ('0'<=ch&&ch<='9') res=res*10+ch-48,ch=nc(); return res*f; } const int maxn=800005; int n,q; bool vis[maxn]; struct data{ int t,x,y,w; inline bool operator<(const
data&b)const {return x<b.x || x==b.x&&y<b.y || x==b.x&&y==b.y&&t<b.t;} }a[maxn],t[maxn]; #define lowbit(x) ((x)&-(x)) ll BIT[maxn],ans[maxn]; inline void ist(int x,int w){ for (int i=x;i<=n;i+=lowbit(i)) BIT[i]+=w; } inline ll ask(int x){ ll res=0; for
(int i=x;i;i-=lowbit(i)) res+=BIT[i]; return res; } void CDQ(int l,int r){ if (l==r) return; int mid=l+r>>1; CDQ(l,mid);CDQ(mid+1,r); for (int i=l;i<=r;i++){ t[i]=a[i]; if (i<=mid) t[i].t=0; } sort(t+l,t+1+r); for (int i=l;i<=r;i++){ if (!t[i].t&&t[i].w) ist(t[i].y,t[i].w); if (t[i].t&&!t[i].w) ans[t[i].t]+=ask(t[i].y); } for (int i=l;i<=r;i++) if (!t[i].t&&t[i].w) ist(t[i].y,-t[i].w); } int main(){ n=red()+1; for (int c=red();c!=3;c=red()) if (c==1){ a[++q].x=red()+1,a[q].y=red()+1; a[q].t=q;a[q].w=red();vis[q]=1; }else{ int x=red()+1,y=red()+1,xx=red()+1,yy=red()+1; a[++q].x=xx;a[q].y=yy;a[q].t=q; a[++q].x=xx;a[q].y=y-1;a[q].t=q; a[++q].x=x-1;a[q].y=yy;a[q].t=q; a[++q].x=x-1;a[q].y=y-1;a[q].t=q; } CDQ(1,q); for (int i=1;i<=q;i++) if (!vis[i]) printf("%lld\n",ans[i]-ans[i+1]-ans[i+2]+ans[i+3]),i+=3; return 0; }