用c语言实现该问题，并给出代码

在C语言中，我们可以使用`set`数据结构来解决这个问题。这里是一个基本的C代码实现，使用了标准库`<stdlib.h>`和`<stdio.h>`：

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

// 定义函数用于创建并操作集合
typedef struct SetNode {
    int value;
    struct SetNode* next;
} SetNode;

SetNode* createSet() {
    SetNode* newNode = (SetNode*)malloc(sizeof(SetNode));
    newNode-1;
    newNode->next = NULL;
    return newNode;
}

void insertIntoSet(SetNode** head, int value) {
    SetNode* newNode = createSet();
    newNode->value = value;

    if (*head == NULL) {
        *head = newNode;
        return;
    }

    SetNode* current = *head;
    while (current->next != NULL && current->next->value < value) {
        current = current->next;
    }
    newNode->next = current->next;
    current->next = newNode;
}

int searchInSet(SetNode* head, int value) {
    SetNode* current = head;
    while (current != NULL) {
        if (current->value == value) {
            return 1; // 找到了
        }
        current = current->next;
    }
    return 0; // 没找到
}

void deleteFromSet(SetNode** head, int value) {
    if (*head == NULL) {
        return;
    }

    if ((*head)->value == value) {
        SetNode* temp = *head;
        *head = (*head)->next;
        free(temp);
        return;
    }

    SetNode* current = *head;
    SetNode* prev = NULL;

    while (current != NULL && current->value != value) {
        prev = current;
        current = current->next;
    }

    if (current != NULL) {
        prev->next = current->next;
        free(current);
    }
}

// 主函数
void calculateDifference(char* A_str, char* B_str, int n, int m) {
    SetNode* setA = createSet();
    SetNode* setB = createSet();

    for (int i = 0; i < n; i++) {
        int val = atoi(A_str + i * 2); // 分离每个整数
        insertIntoSet(&setA, val);
    }

    for (int i = 0; i < m; i++) {
        int val = atoi(B_str + i * 2); // 分离每个整数
        insertIntoSet(&setB, val);
        deleteFromSet(&setB, val); // 更新B集合，移除已知元素
    }

    SetNode* result = createSet();
    for (SetNode* node = setA; node != NULL; node = node->next) {
        if (!searchInSet(setB, node->value)) {
            insertIntoSet(&result, node->value);
        }
    }

    // 输出结果，转换为字符串
    char* output = "";
    SetNode* temp = result;
    while (temp != NULL) {
        output = realloc(output, strlen(output) + 9);
        sprintf(output + strlen(output), "%d ", temp->value);
        temp = temp->next;
    }
    printf("%s\n", output);

    // 清理内存
    deleteFromSet(&setA, -1);
    deleteFromSet(&setB, -1);
    deleteFromSet(&result, -1);
}

int main() {
    int n, m;
    scanf("%d %d", &n, &m);
    char A_str[10001], B_str[10001];
    scanf(" %s %s", A_str, B_str);
    calculateDifference(A_str, B_str, n, m);
    return 0;
}

这个程序首先读取输入的元素数量和集合，然后分别构建A和B的集合。接着从A集合中删除已经在B集合中的元素，形成A-B的结果。最后，打印出结果并清理内存。注意这只是一个基础版本，实际应用中可能需要考虑边界条件、错误处理等因素。