OJ Board

I have tried all test cases on this board, but still got WA...
Could someone help me, please?
thanx!

[c]
#include <stdio.h>
#include <stdlib.h> /* for calloc() */
#include <math.h> /* for sqrt() */
#define POS 1 /* sign(+) */
#define NEG -1 /* sign(-) */

typedef float REAL;
typedef struct node ...