Zerojudge b604

#include <stdio.h>
#include <stdlib.h>

void pntbubbleSort(float array[][2], int size);
void swap(float *a, float *b);

int main(void)
{
    int points;
    scanf("%d", &points);
    while (points != 0){
        float pointArr[points][2];

        for (int i = 0; i < points; ++i){
            float x, y;
            scanf("%f %f", &x, &y);
            pointArr[i][0] = x;
            pointArr[i][1] = y;
        }
        pntbubbleSort(pointArr, points);

        /*
        for (int i = 0; i < points; ++i){
            printf("%f %f\n", pointArr[i][0], pointArr[i][1]);
        }
        */

        int check = 0;
        int xcheck = pointArr[0][0] + pointArr[points - 1][0];
        int ycheck = pointArr[0][1] + pointArr[points - 1][1];
        for (int i = 0; i < points / 2; ++i){
            if (pointArr[i][0] + pointArr[points - i - 1][0] == xcheck &&
                pointArr[i][1] + pointArr[points - i - 1][1] == ycheck){
                ++check;
            }
        }
        if (check == points / 2){
            printf("yes\n");
        } else {printf("no\n");}

        scanf("%d", &points);
    }
}

void pntbubbleSort(float array[][2], int size)
{
    for (int pass = 1; pass < size; ++pass){
        for (int count = 0; count < size - 1; ++count){
            if (array[count][0] > array[count + 1][0]){
                swap(&array[count][0], &array[count + 1][0]);
                swap(&array[count][1], &array[count + 1][1]);
            }
            else if (array[count][0] == array[count + 1][0]){
                if (array[count][1] > array[count + 1][1]){
                    swap(&array[count][0], &array[count + 1][0]);
                    swap(&array[count][1], &array[count + 1][1]);
                }
            }
        }
    }
}

void swap(float *a, float *b)
{
    int hold = *a;
    *a = *b;
    *b = hold;
}