C语言中有哪些耗时操作

在C语言中，有一些耗时操作会影响程序的执行速度和效率。这些操作包括输入输出操作、循环和递归、文件操作、网络通信以及排序和搜索等。本文将逐一介绍这些耗时操作，并给出相应的案例代码。

c
#include 
int main() {
    int num;
    printf("请输入一个整数：");
    scanf("%d", &num);
    printf("您输入的整数是：%d\n", num);
    return 0;
}

c
#include 
int factorial(int n) {
    if (n == 0) {
        return 1;
    } else {
        return n * factorial(n - 1);
    }
}
int main() {
    int num;
    printf("请输入一个正整数：");
    scanf("%d", &num);
    int result = factorial(num);
    printf("%d的阶乘是：%d\n", num, result);
    return 0;
}

c
#include 
int main() {
    FILE *fp;
    char str[100];
    // 向文件中写入数据
    fp = fopen("file.txt", "w");
    fputs("Hello, World!", fp);
    fclose(fp);
    // 从文件中读取数据
    fp = fopen("file.txt", "r");
    fgets(str, 100, fp);
    printf("从文件中读取的数据是：%s\n", str);
    fclose(fp);
    return 0;
}

c
#include 
#include 
#include 
#include 
#include 
int main() {
    int clientSocket;
    char buffer[1024];
    struct sockaddr_in serverAddr;
    socklen_t addr_size;
    // 创建客户端套接字
    clientSocket = socket(PF_INET, SOCK_STREAM, 0);
    // 设置服务器地址信息
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons(7891);
    serverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
    memset(serverAddr.sin_zero, '\0', sizeof serverAddr.sin_zero);
    // 连接服务器
    addr_size = sizeof serverAddr;
    connect(clientSocket, (struct sockaddr *) &serverAddr, addr_size);
    // 接收服务器发送的数据
    recv(clientSocket, buffer, 1024, 0);
    printf("从服务器接收的数据是：%s\n", buffer);
    // 关闭套接字
    close(clientSocket);
    return 0;
}

c
#include 
void quickSort(int arr[], int low, int high) {
    if (low < high) {
        int i = low, j = high;
        int pivot = arr[low];
        while (i < j) {
            while (i < j && arr[j] >= pivot) {
                j--;
            }
            if (i < j) {
                arr[i++] = arr[j];
            }
            while (i < j && arr[i] < pivot) {
                i++;
            }
            if (i < j) {
                arr[j--] = arr[i];
            }
        }
        arr[i] = pivot;
        quickSort(arr, low, i - 1);
        quickSort(arr, i + 1, high);
    }
}
int binarySearch(int arr[], int low, int high, int target) {
    if (low <= high) {
        int mid = (low + high) / 2;
        if (arr[mid] == target) {
            return mid;
        } else if (arr[mid] > target) {
            return binarySearch(arr, low, mid - 1, target);
        } else {
            return binarySearch(arr, mid + 1, high, target);
        }
    }
    return -1;
}
int main() {
    int arr[] = {5, 2, 8, 12, 3, 1, 9};
    int n = sizeof(arr) / sizeof(arr[0]);
    printf("排序前的数组：");
    for (int i = 0; i < n; i++) {
        printf("%d ", arr[i]);
    }
    printf("\n");
    quickSort(arr, 0, n - 1);
    printf("排序后的数组：");
    for (int i = 0; i < n; i++) {
        printf("%d ", arr[i]);
    }
    printf("\n");
    int target = 3;
    int index = binarySearch(arr, 0, n - 1, target);
    if (index != -1) {
        printf("找到目标元素 %d，索引为 %d\n", target, index);
    } else {
        printf("未找到目标元素 %d\n", target);
    }
    return 0;
}