用C语言编写一个程序，采用顺序表表示集合（假设同一个集合中不存在重复的元素），将其按递增的方式排序，并求这样的两个集合的并，交，差。（并，交，差分开编写采用函数调用，设计一个菜单 输入1求并集，输入2求交集，输入3求差集）

好的，以下是代码实现：

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

#define MAXSIZE 100

typedef struct {
    int data[MAXSIZE];
    int length;
} SqList;

void InitList(SqList *L) {
    L->length = 0;
}

void Insert(SqList *L, int x) {
    if (L->length == MAXSIZE) {
        printf("List is full.\n");
        return;
    }
    L->data[L->length++] = x;
}

void Sort(SqList *L) {
    int i, j, temp;
    for (i = 0; i < L->length - 1; i++) {
        for (j = i + 1; j < L->length; j++) {
            if (L->data[i] > L->data[j]) {
                temp = L->data[i];
                L->data[i] = L->data[j];
                L->data[j] = temp;
            }
        }
    }
}

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

void Union(SqList *A, SqList *B, SqList *C) {
    int i, j, k;
    i = j = k = 0;
    while (i < A->length && j < B->length) {
        if (A->data[i] < B->data[j]) {
            C->data[k++] = A->data[i++];
        } else if (A->data[i] > B->data[j]) {
            C->data[k++] = B->data[j++];
        } else {
            C->data[k++] = A->data[i++];
            j++;
        }
    }
    while (i < A->length) {
        C->data[k++] = A->data[i++];
    }
    while (j < B->length) {
        C->data[k++] = B->data[j++];
    }
    C->length = k;
}

void Intersection(SqList *A, SqList *B, SqList *C) {
    int i, j, k;
    i = j = k = 0;
    while (i < A->length && j < B->length) {
        if (A->data[i] < B->data[j]) {
            i++;
        } else if (A->data[i] > B->data[j]) {
            j++;
        } else {
            C->data[k++] = A->data[i++];
            j++;
        }
    }
    C->length = k;
}

void Difference(SqList *A, SqList *B, SqList *C) {
    int i, j, k;
    i = j = k = 0;
    while (i < A->length && j < B->length) {
        if (A->data[i] < B->data[j]) {
            C->data[k++] = A->data[i++];
        } else if (A->data[i] > B->data[j]) {
            j++;
        } else {
            i++;
            j++;
        }
    }
    while (i < A->length) {
        C->data[k++] = A->data[i++];
    }
    C->length = k;
}

void Menu() {
    printf("1. Union\n");
    printf("2. Intersection\n");
    printf("3. Difference\n");
    printf("Please enter your choice (1/2/3): ");
}

int main() {
    SqList A, B, C;
    int i, x, choice;
    InitList(&A);
    InitList(&B);
    InitList(&C);

    printf("Enter set A (separated by spaces, end with -1): ");
    while (scanf("%d", &x) && x != -1) {
        Insert(&A, x);
    }

    printf("Enter set B (separated by spaces, end with -1): ");
    while (scanf("%d", &x) && x != -1) {
        Insert(&B, x);
    }

    Sort(&A);
    Sort(&B);

    Menu();
    scanf("%d", &choice);

    switch (choice) {
        case 1:
            Union(&A, &B, &C);
            printf("A union B: ");
            PrintList(&C);
            break;
        case 2:
            Intersection(&A, &B, &C);
            printf("A intersection B: ");
            PrintList(&C);
            break;
        case 3:
            Difference(&A, &B, &C);
            printf("A difference B: ");
            PrintList(&C);
            break;
        default:
            printf("Invalid choice.\n");
            break;
    }

    return 0;
}

注：此处的 `SqList` 采用顺序表实现。