题解 | #从单向链表中删除指定值的节点#

#include <cmath>
#include <iostream>
#include<map>
#include <sstream>
using namespace std;

int main() {
    map<int, int> list;
    string s;
    int behind = 0;
    int before = 0;
    int num = 0;
    int head = 0;
    int tem;
    int to_delete = 0;
    cin >> num;
    cin >> head;
    list.insert({head, -1});
    getline(cin, s);
    int digit = 0;
    for(int i = s.size()-1;i>=0;i--){
        if(s[i]>='0'&&s[i]<='9'){
            to_delete+=(s[i]-'0')*pow(10,digit);
            digit++;
        }else{
            break;
        }
    }
    s.erase(s.size() - 1, 1);
    istringstream ss(s);
    while (ss >>behind>>before) {
            tem = list[before];
            list[before] = behind;
            list.insert({behind, tem});
    }
    int i = head;
    while (i != -1) {
        if (list[i] == to_delete) {
            tem = list[i];
            list[i] = list[tem];
            list.erase(tem);
            break;
        }
        i = list[i];
    }
    i = head;
    while(i!=-1){
        cout<<i<<' ';
        i = list[i];
    }
}
// 64 位输出请用 printf("%lld")

哈希表实现链表，便于操作，单词插入删除时间复杂度为n