poj2398

这道题是2318的升级版，题意参见2318解题报告，增加了两处难点，一是隔板不按顺序给出，sort一下就行了；二是输出格式有新的要求，要求输出有i个玩具的格子有几个

WA点：1、sort的时候sort(array,array+n,MyCmp)时只是对0~n-1个元素进行sort，而据题意该是0~n

           2、这也是最2的地方，Box写成BOX，冒号后没加空格

代码：#include<iostream>#include<cstdio>#include<algorithm>#include<cstring>using namespace std;#define MAX 1010struct Point{ long x,y;};Point toys[MAX];//存储各个玩具坐标int res[MAX];//res[i]表示第i个格子有几个玩具 i为 0~nint final_res[MAX];//final_res[i]表示有i个玩具的格子有几个 i为0~mPoint up_left,right_down;Point cardboard[MAX];//借用Point存放隔板的两个横坐标，x表示隔板上方横坐标，y表示下方横坐标int n,m;void Input(){ cin >> up_left.x >> up_left.y; cin >> right_down.x >> right_down.y; cardboard[0].x = up_left.x;//这两行将0板设为盒子最左边 cardboard[0].y = up_left.x; for(int i = 1; i <= n; i++) { cin >> cardboard[i].x >> cardboard[i].y;//x代表上方横坐标，y代表下方横坐标 } for(int i = 1; i <= m; i++) { cin >> toys[i].x >> toys[i].y; }}int Cross(const Point & o,const Point& a,const Point b){ return (a.x - o.x) * (b.y - o.y) - (a.y - o.y) * (b.x - o.x);}int BinarySearch(const Point& key)//返回key点所在格子编号+1{ int start = 0; int end = n; int mid; Point up,down; up.y = up_left.y; down.y = right_down.y; while(start <= end) { mid = (start + end) / 2; up.x = cardboard[mid].x; down.x = cardboard[mid].y; if(Cross(down,key,up)<0) end = mid - 1; else start = mid + 1; } return start;}bool MyCmp(const Point& a,const Point &b ){ return a.x <= b.x;}void Compute(){ sort(cardboard,cardboard+n+1,MyCmp); int index; memset(res,0,sizeof(res)); for(int i = 1; i <= m; i++) { index = BinarySearch(toys[i]); res[index-1]++; }}void Output(){ memset(final_res,0,sizeof(final_res)); for(int i = 0; i <= n; i++) { final_res[res[i]]++; } cout << "Box" << endl; for(int i = 1; i <= m; i++) { if(final_res[i] > 0) cout << i << ": " << final_res[i] << endl; }}int main(){ while(cin >> n && n) { cin >> m; Input(); Compute(); Output(); } return 0;}