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。

以下是一个简单的实现，代码中有注释说明：

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

// 定义一个人员信息结构体
typedef struct {
    int id;
    char name[20];
} Person;

// 定义一个循环链表结构体
typedef struct node {
    Person data;
    struct node *next;
} Node, *LinkedList;

// 读入人员信息并建立循环链表
LinkedList createList() {
    FILE *fp = fopen("input.info", "r");
    if (fp == NULL) {
        printf("Fail to open file.");
        exit(1);
    }
    LinkedList head = NULL, tail = NULL;
    while (!feof(fp)) {
        Person person;
        fscanf(fp, "%d %s", &person.id, person.name);
        Node *newNode = (Node *)malloc(sizeof(Node));
        newNode->data = person;
        newNode->next = NULL;
        if (head == NULL) {
            head = newNode;
            tail = newNode;
        } else {
            tail->next = newNode;
            tail = newNode;
        }
    }
    tail->next = head; // 将尾结点的 next 指向头结点，形成循环链表
    fclose(fp);
    return head;
}

// 输出链表中所有结点的信息
void printList(LinkedList head) {
    Node *p = head;
    int i = 1;
    do {
        printf("Node %d: ID=%d, Name=%s\n", i++, p->data.id, p->data.name);
        p = p->next;
    } while (p != head);
}

// 根据编号查找结点
Node *findNodeById(LinkedList head, int id) {
    Node *p = head;
    do {
        if (p->data.id == id) {
            return p;
        }
        p = p->next;
    } while (p != head);
    return NULL;
}

// 根据位置删除结点并返回指向下一个结点的指针值、被删除结点的值和初始位置的值
Node *deleteNodeByPosition(LinkedList head, int pos, Person *deletedPerson, int *initialPos) {
    Node *p = head, *prev = NULL;
    int i = 1;
    while (i < pos && p->next != head) {
        prev = p;
        p = p->next;
        i++;
    }
    if (i < pos) { // 位置值超过了链表长度
        return NULL;
    }
    if (prev == NULL) { // 删除头结点
        prev = head;
        while (prev->next != head) {
            prev = prev->next;
        }
        head = head->next;
        prev->next = head;
    } else {
        prev->next = p->next;
    }
    *deletedPerson = p->data;
    *initialPos = i;
    free(p);
    return prev->next;
}

int main() {
    LinkedList list = createList();
    printf("The linked list is:\n");
    printList(list);

    int id;
    printf("Please enter an ID to search: ");
    scanf("%d", &id);
    Node *node = findNodeById(list, id);
    if (node == NULL) {
        printf("No such node found.\n");
    } else {
        printf("Node with ID=%d and Name=%s is found at position %d.\n", node->data.id, node->data.name, (int)(node - list) + 1);
    }

    int pos;
    printf("Please enter a position to delete: ");
    scanf("%d", &pos);
    Person deletedPerson;
    int initialPos;
    Node *nextNode = deleteNodeByPosition(list, pos, &deletedPerson, &initialPos);
    if (nextNode == NULL) {
        printf("Invalid position.\n");
    } else {
        printf("Node with ID=%d and Name=%s is deleted from position %d.\n", deletedPerson.id, deletedPerson.name, initialPos);
        while (nextNode->next != nextNode) {
            printf("The linked list is:\n");
            printList(nextNode);
            printf("Please enter a position to delete: ");
            scanf("%d", &pos);
            nextNode = deleteNodeByPosition(nextNode, pos, &deletedPerson, &initialPos);
            printf("Node with ID=%d and Name=%s is deleted from position %d.\n", deletedPerson.id, deletedPerson.name, initialPos);
        }
        printf("The last person left is with ID=%d and is at the initial position %d.\n", nextNode->data.id, (int)(nextNode - list) + 1);
    }

    return 0;
}