Leetcode 704 will fail, need to check boundary

[hsinanchen2007]

class Solution {
public:
int search(vector& A, int target) {
int L = 0, R = A.size();
while (L <= R) {
int M = (L + R) / 2;
if (A[M] == target) return M;
if (A[M] < target && A.size() != M + 1) L = M + 1;
else R = M - 1;
}
return -1;
}
};

[lzl124631x]

@hsinanchen2007 not needed. A[M] won't go out of bound. Even if it will, you should check M + 1 != A.size() before accessing A[M]...

[hsinanchen2007]

Thanks for reply. Yes, I know in general it won't fail, but when I review different solutions at that day, there is a weird testcase and that will fail at that day. That's why I added that condition to pass it. It seems like Leetcode already removed that testcase and now it's working fine again. Again, really appreciate your solutions here! If possible, you may try to add comments and explanation to help more people. :-)