class?Solution?{

public:

/*

????二分查找的难点在于区间的控制，此题用的区间是前闭后闭[L,R]

????前闭后闭的二分查找模板如下：

*/

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

????????int?L=0;

????????int?R=nums.size()-1;

????????while(L<=R){//此处有“=”，那么L=R时是有意义的

????????????int?mid?=?L+(R-L)/2;//防止溢出

????????????if(nums[mid]>target){//target在左区间[L,mid-1]

????????????????R=mid-1;//此时nums[mid]一定不等于target，所以赋值为mid-1

????????????}

????????????else?if(nums[mid]<target){//target在右区间[mid+1,R]

????????????????L=mid+1;//此时nums[mid]一定不等于target，所以赋值为mid+1

????????????}

????????????else{

????????????????return?mid;//找到目标值，返回下标

????????????}

????????}

????????return?-1;

????}

};

27. 移除元素