leetcode

0 class Solution {

1 public:

2 vector<int> restoreArray(const vector<vector<int>> &adjacentPairs) {

3 const int n = adjacentPairs.size() + 1;

4 unordered_map<int, vector<int>> um;

5

6 for (const auto &p : adjacentPairs) {

7 um[p[0]].push_back(p[1]);

8 um[p[1]].push_back(p[0]);

9 }

10

11 int start = -1;

12 for (const auto &[k, v] : um) {

13 if (v.size() == 1) {

14 start = k;

15 break;

16 }

17 }

18

19 vector<int> res(n);

20 res[0] = start, res[1] = um[start][0];

21 for (int i = 2; i < n; i++) {

22 res[i] = um[res[i - 1]][0] != res[i - 2] ? um[res[i - 1]][0] : um[res[i - 1]][1];

23 }

24 return res;

25 }

26 };