标签:src cst algorithm ima zoj inline strong ++ string



就是一个树状数组...把询问拆成四个...
考点大概就是把区间询问转化为前缀和相减...
#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
//by NeighThorn
using namespace std;
const int maxn=100000+5;
int n,m,tot,lenx,leny,mpx[maxn<<2],mpy[maxn<<2];
long long ans,tr[maxn<<2];
struct M{
int x,y,id,val;
long long ans;
}q[maxn<<2],node[maxn];
inline bool cmp1(M a,M b){
return a.x<b.x;
}
inline void insert(int x,int y){
for(;x<=leny;x+=x&-x)
tr[x]+=y;
}
inline long long query(int x){
long long res=0;
for(;x;x-=x&-x)
res+=tr[x];
return res;
}
inline bool cmp2(M a,M b){
if(a.id!=b.id) return a.id<b.id;
}
signed main(void){
scanf("%d%d",&n,&m);lenx=leny=n;
for(int i=1;i<=n;i++)
scanf("%d%d%d",&node[i].x,&node[i].y,&node[i].val),
mpx[i]=node[i].x,mpy[i]=node[i].y;
for(int i=1,x1,x2,y1,y2;i<=m;i++){
scanf("%d%d%d%d",&x1,&y1,&x2,&y2);
mpx[++lenx]=x1 ,mpx[++lenx]=x2 ,mpy[++leny]=y1,mpy[++leny]=y2;
mpx[++lenx]=x1-1,mpy[++leny]=y1-1;
q[++tot].x=x1-1,q[tot].y=y1-1,q[tot].id=i,q[tot].val= 1;
q[++tot].x=x1-1,q[tot].y=y2 ,q[tot].id=i,q[tot].val=-1;
q[++tot].x=x2 ,q[tot].y=y1-1,q[tot].id=i,q[tot].val=-1;
q[++tot].x=x2 ,q[tot].y=y2 ,q[tot].id=i,q[tot].val= 1;
}
sort(mpx+1,mpx+lenx+1);
sort(mpy+1,mpy+leny+1);
lenx=unique(mpx+1,mpx+lenx+1)-mpx-1;
leny=unique(mpy+1,mpy+leny+1)-mpy-1;
for(int i=1;i<=n;i++)
node[i].x=lower_bound(mpx+1,mpx+lenx+1,node[i].x)-mpx,
node[i].y=lower_bound(mpy+1,mpy+leny+1,node[i].y)-mpy;
for(int i=1;i<=tot;i++)
q[i].x=lower_bound(mpx+1,mpx+lenx+1,q[i].x)-mpx,
q[i].y=lower_bound(mpy+1,mpy+leny+1,q[i].y)-mpy;
sort(q+1,q+tot+1,cmp1);
sort(node+1,node+n+1,cmp1);
for(int i=1,j=1;i<=tot;i++){
for(;j<=n&&node[j].x<=q[i].x;j++)
insert(node[j].y,node[j].val);
q[i].ans=query(q[i].y);
}
sort(q+1,q+tot+1,cmp2);tot=0;
for(int i=1;i<=m;i++){
ans=0;
tot++;ans+=q[tot].val*q[tot].ans;
tot++;ans+=q[tot].val*q[tot].ans;
tot++;ans+=q[tot].val*q[tot].ans;
tot++;ans+=q[tot].val*q[tot].ans;
printf("%lld\n",ans);
}
return 0;
}
By NeighThorn
标签:src cst algorithm ima zoj inline strong ++ string
原文地址:http://www.cnblogs.com/neighthorn/p/6713667.html