当选择删除功能时，从键盘读入欲删除的元素位置或元素值，按指定方式删除；当选择插入功能时，从键盘读入新元素值和被插入位置，在指定位置插入；当选择查找功能时，从键盘读入欲查找的元素值，返回其位置序号。

以下是一个示例代码，实现了一个简单的线性表，包括插入、删除和查找功能：

#include <stdio.h>

#define MAX_SIZE 100

typedef struct {
    int data[MAX_SIZE];
    int length;
} SeqList;

int locate(SeqList *L, int x) {
    for (int i = 0; i < L->length; i++) {
        if (L->data[i] == x) {
            return i;
        }
    }
    return -1;
}

void insert(SeqList *L, int x, int pos) {
    if (pos < 0 || pos > L->length) {
        printf("Invalid position!\n");
        return;
    }
    if (L->length >= MAX_SIZE) {
        printf("List overflow!\n");
        return;
    }
    for (int i = L->length; i > pos; i--) {
        L->data[i] = L->data[i-1];
    }
    L->data[pos] = x;
    L->length++;
}

void delete(SeqList *L, int x) {
    int pos = locate(L, x);
    if (pos == -1) {
        printf("Element not found!\n");
        return;
    }
    for (int i = pos; i < L->length-1; i++) {
        L->data[i] = L->data[i+1];
    }
    L->length--;
}

void print_list(SeqList *L) {
    printf("List:");
    for (int i = 0; i < L->length; i++) {
        printf(" %d", L->data[i]);
    }
    printf("\n");
}

int main() {
    SeqList L;
    L.length = 0;
    int choice, x, pos;
    while (1) {
        printf("1: insert, 2: delete, 3: search, 4: print, 5: quit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);
        switch (choice) {
            case 1:
                printf("Enter element to insert: ");
                scanf("%d", &x);
                printf("Enter position to insert: ");
                scanf("%d", &pos);
                insert(&L, x, pos);
                break;
            case 2:
                printf("Enter element to delete: ");
                scanf("%d", &x);
                delete(&L, x);
                break;
            case 3:
                printf("Enter element to search: ");
                scanf("%d", &x);
                pos = locate(&L, x);
                if (pos == -1) {
                    printf("Element not found!\n");
                } else {
                    printf("Element found at position %d.\n", pos);
                }
                break;
            case 4:
                print_list(&L);
                break;
            case 5:
                return 0;
            default:
                printf("Invalid choice!\n");
                break;
        }
    }
}

在程序运行时，用户可以根据菜单选择插入、删除、查找或打印线性表，例如：

1: insert, 2: delete, 3: search, 4: print, 5: quit
Enter your choice: 1
Enter element to insert: 2
Enter position to insert: 0
List: 2

1: insert, 2: delete, 3: search, 4: print, 5: quit
Enter your choice: 1
Enter element to insert: 3
Enter position to insert: 1
List: 2 3

1: insert, 2: delete, 3: search, 4: print, 5: quit
Enter your choice: 1
Enter element to insert: 1
Enter position to insert: 0
List: 1 2 3

1: insert, 2: delete, 3: search, 4: print, 5: quit
Enter your choice: 2
Enter element to delete: 2
List: 1 3

1: insert, 2: delete, 3: search, 4: print, 5: quit
Enter your choice: 3
Enter element to search: 3
Element found at position 1.

1: insert, 2: delete, 3: search, 4: print, 5: quit
Enter your choice: 4
List: 1 3

1: insert, 2: delete, 3: search, 4: print, 5: quit
Enter your choice: 5