c_cpp 从未排序的链接列表中删除重复项

Posted 2021-05-14

// https://www.geeksforgeeks.org/remove-duplicates-from-an-unsorted-linked-list/
#include <bits/stdc++.h>
using namespace std;

struct linked_list {
    int data;
    struct linked_list* next;
};
typedef struct linked_list node;

void print (node* n) {
    while (n != NULL) {
        cout<< n->data<< "->";
        n = n->next;
    }
}

node* insert(node* head, int n) {
    node* temp = (node*)malloc(sizeof(node*));
    temp->data = n;
    temp->next = head;
    head = temp;
    return head;
}

void remove(node* head) {
    unordered_set <int> s;
    node* temp = head, *prev = head;
    while (temp) {
        if (s.find(temp->data) != s.end()) {
            prev->next = temp->next;
        }
        else {
            s.insert(temp->data);
            prev=temp;
        }
        temp = temp->next;
    }
}

int main() {
    int n;
    node* head = NULL;
    while (true) {
        cout<< "Enter the elements, and -999 to stop: ";
        cin>>n;
        if (n==-9)
            break;
        else
            head=insert(head,n);
    }
    print(head);
    remove(head);
    cout<< "\n";
    print(head);
}