C语言链表员工记录程序修改求助：改为按员工编号搜索

针对需求：将搜索改为按员工编号、解决找到匹配后仍提示未找到的问题，以下是修改后的完整代码及关键说明：

修改后完整代码 #

#include<stdio.h>
#include<stdlib.h>
#include<string.h>

struct node* createnode(struct node*);
void display(struct node*);
void search(struct node*);

struct node
{
    int emp_num;
    char name[10];
    int Year_service;
    float salary;
    struct node* ptr;
};

int main()
{
    struct node* head;
    int b,i;

    head=NULL;

    while(1)
    {
        printf("\n1-> to enter the employee details\n2->to display All employee details\n3->to search an element\nEnter the value\n");
        scanf("%d",&b);

        switch(b)
        {
            case 1: 
                printf("\nEnter the Number of Employee's Detail you would like to enter\n");
                scanf("%d",&i);
                while(i>0)
                {
                    head=createnode(head);
                    i--;
                }
                break;

            case 2: 
                display(head);
                break;

            case 3: 
                search(head);
                break; 
            default :
                printf("\nEnter Valid Choice \n");
        }
    }
}

void display(struct node* head)
{
    if(head==NULL)
    {
        printf("\nThe list is empty \n");
    }
    else
    {
        while(head!=NULL)
        {
            printf("*****************************************************\n");
            printf("The employee Number :%d\n",head->emp_num);
            printf("The Employee Name :  %s\n",head->name);
            printf("The Salary : %f\n",head->salary);
            printf("Years  serviced : %d\n",head->Year_service);
            head=head->ptr;
        }
    }
}

struct node* createnode(struct node* head)
{
    struct node* newnode = (struct node*)malloc(sizeof(struct node));
    if(newnode == NULL)
    {
        printf("\nMemory allocation failed!\n");
        return head;
    }

    printf("\nEnter the employee number \n");
    scanf("%d",&newnode->emp_num);
    printf("Enter the employee name \n");
    scanf("%s",newnode->name);
    printf("Enter the salary of the employee \n");
    scanf("%f",&newnode->salary);
    printf("Enter the Employee Years of service \n");
    scanf("%d",&newnode->Year_service);

    newnode->ptr=head;
    return newnode;
}

void search(struct node* head)
{
    int target_num;
    int found = 0; // 标记是否找到匹配项

    printf("\nEnter Employee Number\n");
    scanf("%d", &target_num);

    while(head!=NULL)
    {
        if(target_num == head->emp_num)
        {
            found = 1;
            printf("\nThe element is matched\n");
            printf("The employee Number : %d\n",head->emp_num);
            printf("The employee name : %s\n",head->name);
            printf("Salary : %f\n",head->salary);
            printf("Years serviced : %d\n",head->Year_service);
            // 员工编号唯一，找到后直接退出循环
            break;
        }
        head=head->ptr;
    }

    // 遍历结束后统一判断是否找到
    if(!found)
    {
        printf("\nThe element is not matched\n");
    }
}

关键修改点说明 #

1. 切换为按员工编号搜索：

   • 将搜索函数的输入从姓名字符串改为员工编号整数target_num
   • 匹配逻辑从字符串比较strcmp改为整数直接相等判断target_num == head->emp_num

2. 修复错误提示问题：

   • 添加found标记变量，初始为0表示未找到
   • 找到匹配项时设置found=1并跳出循环（员工编号唯一，无需继续遍历）
   • 仅在遍历完所有节点且未找到匹配时，才输出“未找到”提示，避免每一个不匹配节点都输出错误信息

3. 修复内存分配逻辑：

   • 原createnode函数中内存分配失败时访问空指针newnode->ptr的错误，修改为直接返回原头节点并提示内存分配失败

内容的提问来源于stack exchange，提问作者Seeni Mohd