数组

二分查找

class Solution {

public:

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

int left = 0, right = nums.size() - 1;

while(left <= right){

int mid = (right - left) / 2 + left;

int num = nums[mid];

if (num == target) {

return mid;

} else if (num > target) {

right = mid - 1;

} else {

left = mid + 1;

}

}

return -1;

}

};