代码有几个用例过不了，不知道为什么

/*
 * 二分算法
 * 两次二分
 * 先通过二分，找出旋转后的分界点
 * 然后比较target的值，在左区间或者右区间再次进行二分
 *
 */

#include <iostream>
#include <vector>
using namespace std;

int searchNum(vector<int>& nums, int target){

    if(nums.size() == 0) return -1;
    if(nums.size() == 1){
        if(nums[0] == target) return 0;
        else return -1;
    }


    int index = 0; // target的索引

    // 先通过二分，找出旋转后的分界点(右分界点)
    // [>=x, <x]
    int n = nums.size();
    int x = nums[0];
    int l = 0, r = n-1;
    while(l<r){
        int mid = (l+r)/2;
        if(nums[mid]<x) r = mid; // [l, mid][mid+1, r]
        else l = mid+1;
    }
    // 右分界点
    int p = l;

    // target在左区间中，[0, p-1]
    if(target >= x){
        int l = 0, r = p-1;
        // [<target][>=target]
        while(l<r){
            int mid = (l+r)/2;
            if(nums[mid]>=target) r = mid; // [l, mid][mid+1, r]
            else l = mid+1;
        }
        index = r;
    }
    // target在右区间中，[p, n-1]
    else{
        // [<<target][>=target]
        int l = p, r = n-1;
        while(l<r){
            int mid = (l+r)/2;
            if(nums[mid]>=target) r = mid; // [l, mid][mid+1, r]
            else l = mid+1;
        }
        index = r;
    }
    if(nums[index] == target) return index;
    else return -1;
}


int main(){

    vector<int> nums{1,3};
    int target = 3;

    cout<<searchNum(nums, target)<<endl;

    return 0;
}