文件读取数据总是溢出，请问是什么问题？

Question

请问我的这串代码有什么问题吗？为什么从文件中读取数据总是溢出？

typedef struct PolyArray
{
    double coef;
    int exp;
}PolyArray；

int main()
{
    FILE* fp;
    char str[] = "D:\\visualstudio\\数据结构作业2\\input.txt";
    fopen_s(&fp, str, "at");
    if (!fp)
    {
        printf("open file error");
        return 0;
    }
    PolyNode* ha, * hb, * hc;
    PolyArray* array_a = (PolyArray*)malloc(sizeof(PolyArray) * 3);
    PolyArray* array_b = (PolyArray*)malloc(sizeof(PolyArray) * 3);
    if (array_a && array_b)
    {
       for (int i = 0; i < 3; i++)
        {
            fscanf_s(fp, "%lf %d", &array_a[i].coef, &array_a[i].exp);
            fscanf_s(fp, "%lf %d", &array_b[i].coef, &array_b[i].exp);
        }
    }
    CreatePoly(&ha, 3, array_a);
    CreatePoly(&hb, 3, array_b);
    hc = (PolyNode*)malloc(sizeof(PolyNode));
    AddPoly(ha, hb, hc);
    PrintPoly(fp, hc);
    free(ha);
    free(hb);
    free(hc);
    free(array_a);
    free(array_b);
    fclose(fp);

    return 0;
}

Answer 1

整体修改完善如下，改动见注释处，供参考:

#include <stdio.h>
#include <malloc.h>
typedef struct PolyArray
{
    double coef;
    int exp;
}PolyArray;

typedef struct PolyNode
{
    PolyArray data;
    struct PolyNode* next;
}PolyNode;

void CreatePoly(PolyNode** head, int m, PolyArray* array)
{
    PolyNode* prev = NULL;
    *head = (PolyNode*)malloc(sizeof(PolyNode));
    (*head)->next = NULL;
    for (int i = 0; i < m; i++)
    {
        PolyNode* p = (PolyNode*)malloc(sizeof(PolyNode));
        if (p)
        {
            p->data.coef = array[i].coef;
            p->data.exp = array[i].exp;
            p->next = NULL;
            if (!prev)
            {
                prev = *head;
            }
            prev->next = p;
            prev = p;
        }
    }
}

int ComparePoly(PolyNode* a, PolyNode* b)
{
    if (a->data.exp < b->data.exp)
        return 1;
    else if (a->data.exp > b->data.exp)
        return -1;
    else return 0;
}

PolyNode* AddPoly(PolyNode* ha, PolyNode* hb, PolyNode* hc)
{
    PolyNode* p, * q, * newp, * newh;
    p = ha->next; ha->next = NULL;       //修改
    q = hb->next; hb->next = NULL;       //修改
    newh = hc;
    while (p && q)
    {
        switch (ComparePoly(p, q))
        {
        case 1:
            //newp = (PolyNode*)malloc(sizeof(PolyNode)); 修改
            //if (newp)
            //{
                //newp->data.coef = p->data.coef;
                //newp->data.exp = p->data.exp;
                //newp->next = NULL;
            newh->next = p;//newh->next = newp;
            newh = p;      //newh = newp;
            p = p->next;
            //}
            break;
        case -1:
            //newp = (PolyNode*)malloc(sizeof(PolyNode)); 修改
            //if (newp)
            //{
                //newp->data.coef = q->data.coef;
                //newp->data.exp = q->data.exp;
                //newp->next = NULL;
            newh->next = q;    //newh->next = newp;
            newh = q;    //newh = newp;
            q = q->next;
            break;
            //}
        case 0:
            double sum = p->data.coef + q->data.coef;
            if (sum != 0.0)
            {
                //newp = (PolyNode*)malloc(sizeof(PolyNode)); 修改
                //if (newp)
                //{
                //    newp->data.coef = sum;
                //    newp->data.exp = q->data.exp;
                //    newp->next = NULL;
                q->data.coef = sum;
                newh->next = q;
                newh = q;
                q = q->next;
                PolyNode* pt = p;
                p = p->next;
                free(pt);
                //    newh->next = newp;
                //    newh = newp;
                //}
            }
            else {                 //修改
                PolyNode* pt = p;
                p = p->next;
                free(pt);
                pt = q;
                q = q->next;
                free(pt);
            }
            break;
        }
    }
    newh->next = p ? p : q;
    return hc;
}

void PrintPoly(PolyNode* head)    //修改
{
    FILE* fp;                     //修改
    errno_t err;                  //修改
    char str[] = "D:\\input.txt"; //"D:\\visualstudio\\数据结构作业2\\input.txt"
    err = fopen_s(&fp, str, "at");//修改
    if (err != 0)                 //修改
    {
        printf("open file error");
        return;
    }
    PolyNode* s = head->next;
    while (s)
    {
        fprintf(fp, "%lf %d\n", s->data.coef, s->data.exp); //修改
        s = s->next;
    }
    fclose(fp);   //修改
}

void Destory(PolyNode* head)   //修改
{
    PolyNode* p = NULL;
    while (head) {
        p = head;
        head = head->next;
        free(p);
    }
}

int main()
{
    FILE* fp;
    errno_t err;   //修改
    char str[] = "D:\\input.txt";   //"D:\\visualstudio\\数据结构作业2\\input.txt"
    err = fopen_s(&fp, str, "rt");  //修改
    if (err != 0)   //if (!fp)      //修改
    {
        printf("open file error");
        return 0;
    }
    PolyNode* ha, * hb, * hc;
    PolyArray* array_a = (PolyArray*)malloc(sizeof(PolyArray) * 3);
    PolyArray* array_b = (PolyArray*)malloc(sizeof(PolyArray) * 3);
    if (array_a && array_b)
    {
        for (int i = 0; i < 3; i++)
        {
            fscanf_s(fp, "%lf %d\n", &array_a[i].coef, &array_a[i].exp);  //修改
            fscanf_s(fp, "%lf %d\n", &array_b[i].coef, &array_b[i].exp);  //修改
        }
    }
    fclose(fp); //修改

    CreatePoly(&ha, 3, array_a);
    CreatePoly(&hb, 3, array_b);
    hc = (PolyNode*)malloc(sizeof(PolyNode));
    hc->next = NULL;
    AddPoly(ha, hb, hc);
    PrintPoly(hc);
    
    Destory(hc); //free(hc);  修改
    Destory(ha); //free(ha);  修改
    Destory(hb); //free(hb);  修改
    

    free(array_a); 
    free(array_b);
    
    return 0;
}

运行截图：