java-二分法查找

public class halfSel {
    public static void main(String[] args) {
        int s[] = {0,2,11,12,33,43,98,99};
        System.out.println(cal(s,12));
    }

    /**
     *
     * @param arr 数组
     * @param temp 要查找的数字
     * @return 返回改数字在数组中的下标位置，-1则没有
     */
    public static int  cal(int[] arr, int temp){
      int length =   arr.length;

      int min = 0;
      int max = length-1;

      while (min <= max){
          int mid = min + (max - min) / 2;
          if(arr[mid] == (temp)){
                return mid;
          }
          if(arr[mid] < temp){
              min = mid +1;
          }
          if(arr[mid] > temp){
              max = mid -1;
          }
      }
        return -1;
    }
}