```
int result = s - 1;
unordered_set<int> uset;// 存储禁点
for (int i = 0; i < nums.size(); i++) {
if (uset.count(nums[i]) && uset.count(s - nums[i]))
result = result - 2;
if (uset.count(nums[i]))
result--;
}
return result;
```