题解 | #从单向链表中删除指定值的节点#

#include <iostream>
#include <unordered_map>
using namespace std;

int main() {
    int a, b, h, t, d;
    while (cin >> a >> b) { // 注意 while 处理多个 case
        unordered_map<int, int> mp;
        if(a==1) return 0;
        mp[b]=-1;
        for(int i=1; i<a; i++)
        {
            cin>>t>>h;
            if(mp[h]==-1)
            {
                mp[h] = t;
                mp[t] = -1;
            }
            else {
                mp[t] = mp[h];
                mp[h] = t;
            }
        }
        cin>>d;
        if(b==d)
            b = mp[b];
        else {
            for(auto& e: mp)
            {
                if(e.second==d)
                {
                    e.second=mp[d];
                    break;
                }
            }
        }
        cout<<b<<" ";
        while(mp[b]!=-1)
        {
            cout<<mp[b]<<" ";
            b = mp[b];
        }
    }
}