class Solution {
public:
int search(vector<int>& nums, int target) {
//二分查找
int left = 0;
int right = nums.size()-1;
while(left<=right){
int mid = (left+right)/2;
if(nums[mid]==target){
return mid;
}else if(nums[mid]<target){
left = mid+1;
}else{
right = mid-1;
}
}
return -1;
}
};