Arrays.binarySearch方法使用前，需要对数组排序，才能定位值插入位置，因为binarySearch采用二分搜索法,源码:
int low = fromIndex;//0
int high = toIndex - 1;//Array.length -1
while (low <= high) {
int mid = (low + high) >>> 1;
int midVal = a[mid];
if (midVal < key)
low = mid + 1;
else if (midVal > key)
high = mid - 1;
else
return mid; // key found
}
return -(low + 1); // key not found.
九刃 九刃
528***187@qq.com
9年前 (2017-07-10)