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#include "leetcode.h"
class Solution {
public:
int closestMeetingNode(vector<int> &edges, int node1, int node2) {
pair<int, int> p1 = dfs(edges, node1, node2);
pair<int, int> p2 = dfs(edges, node2, node1);
if (p1.second != -1 && p1.first < p2.first)
return p1.second;
else if (p2.second != -1 && p2.first < p1.first)
return p2.second;
else if (p1.first == p2.first) {
if (p1.second < p2.second)
return p1.second;
else
return p2.second;
}
return -1;
}
private:
pair<int, int> dfs(vector<int> &edges, int node1, int node2) {
unordered_map<int, int> um;
int n = edges.size();
vector<int> vis1(n + 2, 0), vis2(n + 2, 0);
um[node1] = 1;
int len = 0;
while (edges[node1] != -1 && vis1[node1] != 1) {
vis1[node1] = 1;
node1 = edges[node1];
um[node1] = len++;
}
pair<int, int> pp = make_pair(INT_MAX, -1);
if (um.find(node2) != um.end()) {
pp = make_pair(um[node2], node2);
return pp;
}
while (edges[node2] != -1 && vis2[node2] != 1) {
vis2[node2] = 1;
node2 = edges[node2];
if (um.find(node2) != um.end()) {
pp = make_pair(um[node2], node2);
return pp;
}
}
return pp;
}
};
int main() {
Solution obj;
vector<int> edges1 = {2, 2, 3, -1}, edges2 = {1, 2, -1};
cout << obj.closestMeetingNode(edges1, 0, 2) << endl; // expect: 2
cout << obj.closestMeetingNode(edges2, 0, 2) << endl; // expect: 2
}
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