Solution.cpp

class Solution {
public:
    bool isStrobogrammatic(string num) {
        vector<int> d = {0, 1, -1, -1, -1, -1, 9, -1, 8, 6};
        for (int i = 0, j = num.size() - 1; i <= j; ++i, --j) {
            int a = num[i] - '0', b = num[j] - '0';
            if (d[a] != b) {
                return false;
            }
        }
        return true;
    }
};