func search(nums []int, target int) int {
    left := 0
    right := len(nums) - 1
    for left <= right{
        mid := left + (right-left) / 2
        // mid := left + (right-left) * 618 / 1000 //黄金分割，略优化时间复杂度。
        if(nums[mid] > target){
            right = mid - 1
        }else if(nums[mid] < target){
            left = mid + 1
        }else{
            return mid
        }
    }
    return -1
}