【幾何—正方形覆蓋】hdu 4007

暴力，先確定左右邊界，再遍曆y，注意剪枝

#include <list>#include <map>#include <set>#include <queue>#include <string>#include <deque>#include <stack>#include <algorithm>#include <iostream>#include <iomanip>#include <cstdio>#include <cmath>#include <cstdlib>#include <limits.h>#include <time.h>#include <string.h>using namespace std;#define LL long long#define PI acos(-1.0)#define MAX INT_MAX#define MIN INT_MIN#define eps 1e-8#define FRE freopen("a.txt","r",stdin)#define MOD 1000000007#define N  1004int n;struct point{    int x,y;}p[N];int ll;int Y[N];bool cmp(point a,point b){    return a.x<b.x;}int gao(int l,int r){    int i,j;    int cnt=0;    for(i=0;i<n;i++){        if(p[i].x>=l && p[i].x<=r)        Y[cnt++]=p[i].y;    }    sort(Y,Y+cnt);    int maxm=0;    int tt=-1;    for(i=0;i<cnt;i++){        int tot=0;        if(Y[i]==tt)continue;        tt=Y[i];        j=i;        while(j<cnt&& Y[j]>=Y[i] && Y[j]<=Y[i]+ll){            j++;        tot++;        }        if(tot>maxm)maxm=tot;    }    return maxm;}int main(){    while(scanf("%d%d",&n,&ll)!=EOF){        int i,j;        for(i=0;i<n;i++){            scanf("%d%d",&p[i].x,&p[i].y);        }        sort(p,p+n,cmp);        int ans=0;        int tt=-1;        for(i=0;i<n;i++){            int sum;            if(p[i].x==tt)continue;            tt=p[i].x;            sum=gao(p[i].x,p[i].x+ll);            if(sum>ans)ans=sum;        }        printf("%d\n",ans);    }    return 0;}