解析
经典二分,重点在于左闭右闭区间约定好后,根据定义更新边界
代码
cpp
class Solution {
public:
int search(vector<int>& nums, int target) {
int left = 0, right = nums.size() - 1;
while(left <= right){
int mid = (left + right) / 2;
if(nums[mid] < target){
left = mid + 1;
}else if(nums[mid] > target){
right = mid - 1;
}else{
return mid;
}
}
return -1;
}
};