Question

#include <stdio.h>
#include <stdlib.h>
struct Node
{
    int data;
    struct Node* next;
};
struct Node* head;
void insertAtFront(int data)
{
    struct Node* temp = (struct Node*)malloc(sizeof(struct Node));
    temp->data = data;
    temp->next = NULL;
    temp->next = head;
    head = temp;
    return ;
}
void displayAll()
{
    struct Node* temp = head;
    while(temp != NULL)
    {
     printf("%d\t",temp->data);
     temp = temp->next;
    }
    printf("\n");
}
void insertAtNthPostion(int data,int key)
{
    int i;
    struct Node* temp = (struct Node*)malloc(sizeof(struct Node));
    temp->data = data;
    temp->next = NULL;
    struct Node* temp1 = head;
    for(i=1;i<key;i++)
        temp1 = temp1->next;
    temp->next = temp1->next;
    temp1=temp;
    displayAll();
    return;
}
int main()
{
    int num, i, data, key;
    head= NULL;
    printf("\nHow many data u want to insert? ");
    scanf("%d", &num);
    for(i=0; i < num; i++)
    {
        printf("\nEnter the data u want to insert:");
        scanf("%d", &data);
        insertAtFront(data);
    }
    displayAll();
    printf("Enter the data and position u want to insert:\n");
    scanf("%d%d", &data, &key);
    insertAtNthPostion(data,key);
    return 0;
}

我已经尝试过这个实现但是值没有改变，我的输出显示如下：

Enter the data u want to insert:
5
5       3       2       1       2
Enter the data and position u want to insert:
265498
2
5       3       2       1       2

Answer 1

您需要将上一个节点->next设置为新节点。

您还忘记了for循环{}上的花括号。

您也忘记删除原始节点，但这不会改变结果，但会浪费内存..

#include <stdio.h>
#include <stdlib.h>
struct Node
{
    int data;
    struct Node* next;
};
struct Node* head;
void insertAtFront(int data)
{
    struct Node* temp = (struct Node*)malloc(sizeof(struct Node));
    temp->data = data;
    temp->next = NULL;
    temp->next = head;
    head = temp;
    return ;
}
void displayAll()
{
    struct Node* temp = head;
    while(temp != NULL)
    {
     printf("%d\t",temp->data);
     temp = temp->next;
    }
    printf("\n");
}
void insertAtNthPostion(int data,int key)
{
    int i;
    struct Node* new_node = (struct Node*)malloc(sizeof(struct Node));
    new_node->data = data;
    new_node->next = NULL;
    struct Node* current = head;
    struct Node* previous = NULL;
    struct Node* temp = NULL;
    for(i=1;i<key;i++) {
        previous = current;
        current = current->next;
    }
    new_node->next = current->next;
    if (previous != NULL)
        previous->next = new_node;
    else
        head = new_node;
    free(current); //Release the old node's memory
    displayAll();
    return;
}
int main()
{
    int num, i, data, key;
    head= NULL;
    printf("\nHow many data u want to insert? ");
    scanf("%d", &num);
    for(i=0; i < num; i++)
    {
        printf("\nEnter the data u want to insert:");
        scanf("%d", &data);
        insertAtFront(data);
    }
    displayAll();
    printf("Enter the data and position u want to insert:\n");
    scanf("%d%d", &data, &key);
    insertAtNthPostion(data,key);
    return 0;
}

更好的解决方案：

虽然更好的解决方案是更改所选节点的数据，但不创建新节点：

void insertAtNthPostion(int data,int key)
{
    struct Node* current = head;
    int i;
    for(i=1;i<key;i++) {
        current = current->next;
    }
    current->data = data;
    displayAll();
}

结果：

任何一种方法的结果都会给你：

Enter the data u want to insert:3
3       2       1
Enter the data and position u want to insert:
4
1
4       2       1

Linkedlist-在第N个位置插入

1 个答案:

更好的解决方案：

结果：