#include<stdio.h>
#include<stdlib.h>
const int maxN=700;
typedef struct doue
{
	int x,y;
	bool operator==(doue b)
	{
		if(x==b.x&&y==b.y)
			return 1;
		return 0;
	}
}doue;
doue pos[maxN],slope[maxN];
int gcd(int a,int b)
{
	int temp;
	while(b)
	{
		temp=b;
		b=a%b;
		a=temp;
	}
	return a;
}
int cmp(const void *a,const void *b)
{
	if((*(doue*)a).y!=(*(doue*)b).y)
		return (*(doue*)a).y-(*(doue*)b).y;
	return (*(doue*)a).x-(*(doue*)b).x;
}
int main()
{
    freopen("in.txt","r",stdin);
	int i,j,N,R,count,ans,k,temp;
	while(scanf("%d",&N)!=EOF&&N)
	{
		for(i=1;i<=N;i++)
			scanf("%d%d",&(pos[i].x),&(pos[i].y));
		for(i=1,ans=0;i<=N;i++)
		{
			for(j=1,k=1;j<=N;j++)
			{
				if(i!=j)
				{
					slope[k].x=pos[i].x-pos[j].x;
					slope[k].y=pos[i].y-pos[j].y;
					temp=gcd(slope[k].x>0?slope[k].x:-slope[k].x,slope[k].y>0?slope[k].y:-slope[k].y);
					slope[k].x/=temp;
					slope[k].y/=temp;
					if(slope[k].y<0)
					{
						slope[k].x=-slope[k].x;
						slope[k].y=-slope[k].y;
					}
					k++;
				}
			}
			qsort(slope,k-1,sizeof(slope[0]),cmp);
			if(k-1)
			{
			   for(j=2,count=1;j<N;j++)
				if(slope[j]==slope[j-1])
				{
					count++;
				}
				else
				{
					if(ans<count)ans=count;
					count=1;
				}
			    if(ans<count)ans=count;
			}
		}
		printf("%d\n",ans+1);
	}
	return 0;
}

• Re:wa到死，自测一百组数据，怎么回事啊，跪求高手 (1538) 20150082 2017-07-19 09:47:37