用C语言再写一个读入数据生成链表并处理的程序：⚫从上述input.ifo文件读入人员信息，正向建立线性表，使用循环链表方式存储；⚫输出线性表各结点的值和在线性表的位置值到屏幕；⚫键盘输入编号值S，在线性表中查找到编号为S的结点并输出结点的值，包括名字和随机编号（需要测试查找到和查找不到两种情况）；⚫键盘输入位置值M，从线性表中1号结点开始向后报数，将报M的结点从线性表中删除，并输出该结点的编号和初始位置；（提示：可以将按位置删除函数改造成一个新的删除函数，删除的同时返回指向下一个结点的指针值、被删除结点的值；初始位置的值，可以考虑在建立循环链表时保存到结点内）⚫从刚才被删除人的下一个人开始重复上述步骤，直至最后只剩下一个人为止；⚫输出最后剩余一个人的编号和在线性表的初始位置。

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

typedef struct Node {
    char name[20];
    int id;
    struct Node *next;
} Node;

int createList(Node **head);
void printList(Node *head);
Node *searchNode(Node *head, int id);
Node *deleteNode(Node *head, int pos);

int main() {
    Node *head = NULL;
    int s, m;
    int len = createList(&head);
    printf("The list is:\n");
    printList(head);
    printf("Please input a id to search: ");
    scanf("%d", &s);
    Node *node = searchNode(head, s);
    if (node == NULL) {
        printf("Can't find the node.\n");
    } else {
        printf("The node is: %s, %d\n", node->name, node->id);
    }
    printf("Please input a position to delete: ");
    scanf("%d", &m);
    while (len > 1) {
        head = deleteNode(head, m);
        len--;
        printf("Deleted node is: %s, %d, initial pos: %d\n", head->name, head->id, m);
        printf("The list is:\n");
        printList(head);
        printf("Please input a position to delete: ");
        scanf("%d", &m);
    }
    printf("The last node is: %s, %d, initial pos: %d\n", head->name, head->id, 1);
    free(head);
    return 0;
}

int createList(Node **head) {
    FILE *fp;
    if ((fp = fopen("input.info", "r")) == NULL) {
        printf("Can't open file.\n");
        exit(1);
    }
    Node *p = (Node *)malloc(sizeof(Node));
    *head = p;
    int len = 0;
    while (fscanf(fp, "%s %d", p->name, &p->id) != EOF) {
        len++;
        p->next = (Node *)malloc(sizeof(Node));
        p = p->next;
    }
    free(p);
    fclose(fp);
    p->next = *head; // make it a circular linked list
    return len;
}

void printList(Node *head) {
    Node *p = head;
    int pos = 1;
    do {
        printf("Pos: %d, Name: %s, ID: %d\n", pos++, p->name, p->id);
        p = p->next;
    } while (p != head);
}

Node *searchNode(Node *head, int id) {
    Node *p = head;
    do {
        if (p->id == id) {
            return p;
        }
        p = p->next;
    } while (p != head);
    return NULL;
}

Node *deleteNode(Node *head, int pos) {
    Node *p = head;
    Node *prev = NULL;
    int i = 1;
    while (i < pos) {
        prev = p;
        p = p->next;
        i++;
    }
    if (p == head) {
        head = p->next;
    }
    prev->next = p->next;
    free(p);
    return prev->next;
}