Sum without highest and lowest number

解题思路：一次循环，双管齐下

int sum(int* numbers, int numbersCount) {
  if (numbersCount==0 || numbersCount==1) return 0;
  int min = numbers[0],max = numbers[0],sum=numbers[0];
  for (int i=1;i<numbersCount;i++) {
  	sum+=numbers[i];
  	min = min<numbers[i]?min:numbers[i];
  	max = max>numbers[i]?max:numbers[i];
  } 
  
  return sum-min-max;
}