class Solution {
public:
int duplicateInArray(vector[HTML_REMOVED]& nums) {
int l = 1, r = nums.size();
while (l < r)
{
int mid = l + r >> 1;
int res = 0;
for (auto x : nums) res += x >= l && x <= mid;
if (res > mid - l + 1) r = mid;
else l = mid + 1;
}
return r;
}
};