return res;
}
};
// Solution 2: time O(nlogn); space O(1)
class Solution {
public:
vector<vector<int>> findDifference(vector<int> &nums1, vector<int> &nums2) {
vector<vector<int>> res(2);
int i = 0, j = 0;
sort(nums1.begin(), nums1.end());
sort(nums2.begin(), nums2.end());
while (i < nums1.size() && j < nums2.size()) {
while (i < nums1.size() - 1 && nums1[i] == nums1[i + 1]) i++;
while (j < nums2.size() - 1 && nums2[j] == nums2[j + 1]) j++;
if (i >= nums1.size() || j >= nums2.size())
break;
else if (nums1[i] < nums2[j])
res[0].push_back(nums1[i++]);
else if (nums1[i] > nums2[j])
res[1].push_back(nums2[j++]);
else
i++, j++;
}
while (i < nums1.size()) {
res[0].push_back(nums1[i]);
while (++i < nums1.size() && nums1[i - 1] == nums1[i])
;
}
while (j < nums2.size()) {
res[1].push_back(nums2[j]);
while (++j < nums2.size() && nums2[j - 1] == nums2[j])
;
}
return res;
}
};
// Solution 3: time O(1); space O(n)
class Solution {
public:
vector<vector<int>> findDifference(vector<int> &nums1, vector<int> &nums2) {
vector<vector<int>> res(2);
bitset<2002> bs1, bs2;
for (auto num : nums1) bs1.set(num + 1000);
for (auto num : nums2) bs2.set(num + 1000);
for (int i = 0; i < 2002; i++) {
if (bs1[i] && bs2[i])
continue;
else if (bs1[i])
res[0].push_back(i - 1000);
else if (bs2[i])
res[1].push_back(i - 1000);
}
return res;
O
}
};