Binary Search:35. Search Insert Position

给出一个数组，和一个target，如果target在数组中，返回该数字的下标，如果不存在在数组中，返回插入这个数字的下标。

class Solution {public:    int searchInsert(vector<int>& nums, int target) {        if(nums[0] >= target)    return 0;        if(nums[nums.size()-1] < target)    return nums.size();        for(int i = 1; i < nums.size(); ++i)        {            if(nums[i] == target || nums[i] > target)   return i;        }    }};

二分搜索的方法：

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