uva270-共线点

#include<stdio.h>
#include<math.h>
#include<algorithm>
//#define LOCAL
using namespace std;
#define MAX_LEN 710
typedef struct point {
    double x, y;
}Point;
Point setP[MAX_LEN];
double xielv[MAX_LEN];
int maxp;
void Solve(int n)
{
    for(int i=0; i<n; i++) {
        int spe=1; int pos=0;
        for(int j=i+1; j<n; j++) {
            if(fabs(setP[j].x-setP[i].x)<1e-7) spe++;
            else xielv[pos++] = (setP[i].y-setP[j].y)/(setP[i].x-setP[j].x);
        }
        sort(xielv, xielv+pos);
        int x=2; int maxpo = spe; xielv[pos]=3.14159;　　//随便写的
        for(int k=0; k<pos; k++)
            if(fabs(xielv[k]-xielv[k+1])<1e-7) x++;
            else { if(x>maxpo) maxpo=x; x=2; }
        if(maxpo>maxp) maxp = maxpo;
    }
    printf("%d\n", maxp);
}
int main()
{
    #ifdef LOCAL
        freopen("data.txt", "r", stdin);
        freopen("ans.txt", "w", stdout);
    #endif
    int n;
    scanf("%d", &n);
    getchar(); getchar();
    while(n--) {
        int ch = 0; int p = 0;
        ch=getchar();
        while(ch != ‘\n‘ && ch!=EOF) {
            int x, y;
            ungetc(ch, stdin);
            scanf("%d%d", &x, &y);
            setP[p].x = x; setP[p].y = y; p++;
            getchar(); ch = getchar();
        }
        maxp = 0;
        Solve(p);
        if(n) printf("\n");
    }
    return 0;
}