BZOJ 1199 HNOI 2005 汤姆的游戏 计算几何

题目大意

给出若干个图形，这些图形中有些是矩形，剩下的是圆形。还有一些点，问每个点在多少个图形里面。

思路

题目没写数据范围，其实是25w。敢O(n^2)暴力么？没错这个题就是暴力。只需用二分处理一维坐标然后第二维暴力就行了。

CODE

#define _CRT_SECURE_NO_WARNINGS#include <cmath>#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>#define MAX 250010using namespace std;struct Point{    double x,y;    Point(double _,double __):x(_),y(__) {}    Point() {}    bool operator <(const Point &a)const {        return x < a.x;    }    void Read() {        scanf("%lf%lf",&x,&y);    }};inline double Calc(const Point &a,const Point &b){    return sqrt((a.x - b.x) * (a.x - b.x) + (a.y - b.y) *(a.y - b.y));}struct _Point:Point{     int id;}point[MAX];int ans[MAX];int graphs,points;struct Square{    Point p1,p2;    void Read() {        double x1,y1,x2,y2;        scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2);        p1 = Point(min(x1,x2),min(y1,y2));        p2 = Point(max(x1,x2),max(y1,y2));    }    bool InRange(double y) {        return y > p1.y && y < p2.y;    }    void Count() {        int start = upper_bound(point + 1,point + points + 1,p1) - point;        int end = lower_bound(point + 1,point + points + 1,p2) - point - 1;        for(int i = start; i <= end; ++i)            if(InRange(point[i].y))                ++ans[point[i].id];    }}square[MAX];struct Circle{    Point p;    double r;    void Read() {        p.Read();        scanf("%lf",&r);    }    bool InRange(const Point &a) {        return Calc(a,p) < r;    }    void Count() {        int start = upper_bound(point + 1,point + points + 1,Point(p.x - r,0)) - point;        int end = lower_bound(point + 1,point + points + 1,Point(p.x + r,0)) - point - 1;        for(int i = start; i <= end; ++i)            if(InRange(point[i]))                ++ans[point[i].id];    }}circle[MAX];int squares,circles;char s[10];int main(){    cin >> graphs >> points;    for(int i = 1; i <= graphs; ++i) {        scanf("%s",s);        if(s[0] == 'r')            square[++squares].Read();        else            circle[++circles].Read();    }    for(int i = 1; i <= points; ++i) {        point[i].Read();        point[i].id = i;    }    sort(point + 1,point + points + 1);    for(int i = 1; i <= squares; ++i)        square[i].Count();    for(int i = 1; i <= circles; ++i)        circle[i].Count();    for(int i = 1; i <= points; ++i)        printf("%d\n",ans[i]);    return 0;}