用c语言，不是c++编写程序员工绩效有编号（int）、姓名（字符数组）、部门（字符数组）、绩效分数（float）等属性 使用结构体表示员工绩效 使用全局结构体数组存放绩效数据（最多1000个员工） 再定义一个全局结构体数组用来排序； 定义一个表示实际记录数量的全局变量（初值为0） 功能要求：  创建员工绩效记录  显示所有员工绩效记录  清空所有记录  创建员工绩效记录  显示所有员工绩效记录

以下是用C语言编写的员工绩效管理系统的代码：

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

#define MAX_EMPLOYEE 1000

typedef struct {
    int id;
    char name[20];
    char department[20];
    float score;
} Employee;

Employee employees[MAX_EMPLOYEE];
Employee sortedEmployees[MAX_EMPLOYEE];
int numEmployees = 0;

void addEmployee() {
    if (numEmployees >= MAX_EMPLOYEE) {
        printf("Error: Maximum number of employees reached.\n");
        return;
    }

    Employee newEmployee;
    newEmployee.id = numEmployees + 1;

    printf("Enter name: ");
    scanf("%s", newEmployee.name);

    printf("Enter department: ");
    scanf("%s", newEmployee.department);

    printf("Enter score: ");
    scanf("%f", &newEmployee.score);

    employees[numEmployees] = newEmployee;
    sortedEmployees[numEmployees] = newEmployee;
    numEmployees++;

    printf("Employee added successfully.\n");
}

void displayEmployees(Employee *employeeList, int numEmployees) {
    printf("%-5s %-20s %-20s %-10s\n", "ID", "Name", "Department", "Score");
    for (int i = 0; i < numEmployees; i++) {
        printf("%-5d %-20s %-20s %-10.2f\n", employeeList[i].id, employeeList[i].name, employeeList[i].department, employeeList[i].score);
    }
}

void displayAllEmployees() {
    displayEmployees(employees, numEmployees);
}

void clearEmployees() {
    numEmployees = 0;
    printf("All employee records cleared.\n");
}

int compareEmployees(const void *a, const void *b) {
    Employee *employeeA = (Employee *) a;
    Employee *employeeB = (Employee *) b;

    if (employeeA->score < employeeB->score) {
        return 1;
    } else if (employeeA->score > employeeB->score) {
        return -1;
    } else {
        return 0;
    }
}

void sortEmployees() {
    qsort(sortedEmployees, numEmployees, sizeof(Employee), compareEmployees);
}

void displayTopEmployees(int numTopEmployees) {
    sortEmployees();
    printf("Top %d employees:\n", numTopEmployees);
    displayEmployees(sortedEmployees, numTopEmployees);
}

int main() {
    int choice;

    while (1) {
        printf("\n");
        printf("1. Add employee\n");
        printf("2. Display all employees\n");
        printf("3. Clear all employees\n");
        printf("4. Display top employees\n");
        printf("5. Exit\n");
        printf("\n");

        printf("Enter choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                addEmployee();
                break;
            case 2:
                displayAllEmployees();
                break;
            case 3:
                clearEmployees();
                break;
            case 4:
                int numTopEmployees;
                printf("Enter number of top employees to display: ");
                scanf("%d", &numTopEmployees);
                displayTopEmployees(numTopEmployees);
                break;
            case 5:
                printf("Exiting program.\n");
                exit(0);
            default:
                printf("Invalid choice.\n");
                break;
        }
    }

    return 0;
}

以上代码实现了以下功能：

1. 添加员工绩效记录
2. 显示所有员工绩效记录
3. 清空所有员工绩效记录
4. 显示绩效最高的员工
5. 退出程序

该程序使用了结构体来表示员工绩效，并使用全局结构体数组 `employees` 存放所有员工绩效数据。另外，还定义了一个全局结构体数组 `sortedEmployees` 用来排序，以及一个表示实际记录数量的全局变量 `numEmployees`。