Q10_delete_node_in_a_linked_list.cpp

// There is a singly-linked list head and we want to delete a node node in it.

// You are given the node to be deleted node. You will not be given access to the first node of head.

// All the values of the linked list are unique, and it is guaranteed that the given node node is not the last node in the linked list.

// Delete the given node. Note that by deleting the node, we do not mean removing it from memory. We mean:

// The value of the given node should not exist in the linked list.
// The number of nodes in the linked list should decrease by one.
// All the values before node should be in the same order.
// All the values after node should be in the same order.

// Example 1:
// Input: head = [4,5,1,9], node = 5
// Output: [4,1,9]
// Explanation: You are given the second node with value 5, the linked list should become 4 -> 1 -> 9 after calling your function.

// Example 2:
// Input: head = [4,5,1,9], node = 1
// Output: [4,5,9]
// Explanation: You are given the third node with value 1, the linked list should become 4 -> 5 -> 9 after calling your function.

#include<bits/stdc++.h>
using namespace std;

struct ListNode {
    int val;
    ListNode *next;
    ListNode() : val(0), next(nullptr) {}
    ListNode(int x) : val(x), next(nullptr) {}
    ListNode(int x, ListNode *next) : val(x), next(next) {}
};

class Solution {
public:
    void deleteNode(ListNode* node) {
        ListNode *temp = node->next;
        node->val = temp->val;
        node->next = node->next->next;
    }
};

// Time Complexity  : O(1)
// Space Complexity : O(1)