大整数问题 （除法暂时有问题）

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

typedef struct bigInt {
    char* num;//指向长整数数组，序号0中保存着最低位，也就是倒序存放
    char minus;//符号，1表示正数，-1表示符数
    int digit;//保存位数
}BigInt, *pBigInt;

void bigIntTrans(pBigInt num1);//将字符串转化成数字表示
void bigIntTrim(pBigInt num1);//整理大整数，去掉前面得0
void bigIntPrint(pBigInt result);
int bigIntEqual(pBigInt num1, pBigInt num2);//比较两个大整数大小
void bigIntAdd(pBigInt num1, pBigInt num2, pBigInt result);
void bigIntAdd1(pBigInt num1, pBigInt num2, pBigInt result);//同号相加
void bigIntSub1(pBigInt num1, pBigInt num2, pBigInt result);//用于异号相加
void bigIntSub(pBigInt num1, pBigInt num2, pBigInt result);//减法
void bigIntMul(pBigInt num1, pBigInt num2, pBigInt result);//乘法
void bigIntDiv(pBigInt num1, pBigInt num2, pBigInt result, pBigInt residue);//除法

int main(void) {
    bigInt num1, num2, result, residue;
    int i = 0, len;
    char op;
    
    printf("输入最大数的位数:");
    scanf("%d", &len);
    if (!(num1.num = (char*)malloc(sizeof(char) * (len + 1)))) { printf("内存分配失败
"); exit(0); }
    num1.digit = len + 1;
    if (!(num2.num = (char*)malloc(sizeof(char) * (len + 1)))) { printf("内存分配失败
"); exit(0); }
    num2.digit = len + 1;
    if (!(result.num = (char*)malloc(sizeof(char) * (len + 1)))) { printf("内存分配失败
"); exit(0); }
    result.digit = 2 * len + 1;
    for (i = 0; i < result.digit; i++)    result.num[i] = 0;
    printf("选择大整数运算(+,-,*,/): ");
    fflush(stdin);//刷新标准输入缓冲区，把输入缓冲区里的东西丢弃
    scanf(" %c", &op);
    switch (op) {
    case '+':
        printf("
输入被加数:");    scanf("%s", num1.num);
        printf("
输入加数:");    scanf("%s", num2.num);
        bigIntTrans(&num1);
        bigIntTrans(&num2);
        bigIntAdd(&num1, &num2, &result);
        break;
    case '-':
        printf("
输入被减数:");    scanf("%s", num1.num);
        printf("
输入减数:");    scanf("%s", num2.num);
        bigIntTrans(&num1);
        bigIntTrans(&num2);
        bigIntSub(&num1, &num2, &result);
        break;
    case '*':
        printf("
输入被乘数:");    scanf("%s", num1.num);
        printf("
输入乘数:");    scanf("%s", num2.num);
        bigIntTrans(&num1);
        bigIntTrans(&num2);
        bigIntMul(&num1, &num2, &result);
        break;
    case '/':
        printf("
输入被除数:");    scanf("%s", num1.num);
        printf("
输入除数:");    scanf("%s", num2.num);
        bigIntTrans(&num1);
        bigIntTrans(&num2);
        if (num2.digit == 1 && num2.num[0] == '0')    printf("除数不能为0!
");
        else bigIntDiv(&num1, &num2, &result, &residue);
        break;
    }

    if (op == '/') {
        if (!(num2.digit == 1 && num2.num[0] == '0')) {
            printf("商:");    bigIntPrint(&result);
            printf("	余数:");    bigIntPrint(&residue);
        }
    }
    else {printf("结果:");    bigIntPrint(&result);}


    return 0;
}

void bigIntTrans(pBigInt num1) {
    char* t;
    int i, k, len;

    len = strlen(num1->num);
    if (!(t = (char*)malloc(sizeof(char) * len))){printf("内存分配失败!
");exit(0); }
    i = 0;
    num1->minus = 1;//默认为正
    if (num1->num[0] == '-') { num1->minus = -1; i++; }//若第一个字符试'-'，那么则是负数
    k = 0;
    while (num1->num[i] != '') {
        if (num1->num[i] >= '0' && num1->num[i] <= '9') { t[k++] = num1->num[i] - '0'; }//将ASCII码转化成对应得数字
        i++;
    }

    for (i = 0; i < num1->digit; i++)    num1->num[i] = 0;//数组清空
    num1->digit = k;//转换后得位数
    for (i = 0, k--; k >= 0; k--, i++)    num1->num[i] = t[k];//将临时数组 各位 反置 后存到num中

    bigIntTrim(num1);

}

void bigIntTrim(pBigInt num1) {
    int i;
    //从高位检查是否为0
    for (i = num1->digit - 1; i >= 0; i--) { if (num1->num[i] != 0)    break; }//遇到不为0得最高位,跳出循环
    if (i < 0) { num1->digit = 1; num1->num[0] = 0; }
    else num1->digit = i + 1;//余数位数，因为i对应的是下标,比如对应的i=4，那么下标为0，1，2，3，4的位置上都有数，则为5位数

}

void bigIntPrint(pBigInt result) {
    int i;

    if (result->minus == -1) printf("-"); 
    if (result->digit == 1 && result->num[0] == 0) printf("0
");
    else {
        for (i = result->digit - 1; i >= 0; i--)
            printf("%d", result->num[i]);
    }
}

int bigIntEqual(pBigInt num1, pBigInt num2) {
    int i;

    if (num1->digit > num2->digit)    return 1;
    else if (num1->digit < num2->digit)    return -1;
    else {
        i = num1->digit - 1;
        while (i >= 0) {
            if (num1->num[i] > num2->num[i])    return 1;
            else if (num1->num[i] < num2->num[i])    return -1;
            else i--;
        }
    }
    return 0;
}

void bigIntAdd(pBigInt num1, pBigInt num2, pBigInt result) {
    int i = bigIntEqual(num1, num2);

    if (i < 0) { pBigInt t; t = num1; num1 = num2; num2 = t; }
    if (num1->minus * num2->minus < 0) {//符号相同，则加法，不同则减法
        if (i == 0) {//如果两个数是相等的
            result->digit = 1;//结果长度为1位数，就是数值0
            result->minus = 1;//结果为正号
            result->num[0] = 0;//结果为0
            return;
        }
        bigIntSub1(num1, num2, result);//减法
    }
    else bigIntAdd1(num1, num2, result);
}

void bigIntAdd1(pBigInt num1, pBigInt num2, pBigInt result) {
    int i, carry = 0;//carry代表的 进位
    
    result->minus = num1->minus;
    for (i = 0; i < num1->digit; i++) { result->num[i] = num1->num[i]; }
    for (i = 0; i < num2->digit; i++) {
        result->num[i] = result->num[i] + num2->num[i] + carry;//将对应的数和进位数相加
        carry = result->num[i] / 10;//计算进位数据
        result->num[i] = result->num[i] % 10;//保留一位
    }

    if (carry)    result->num[i] = result->num[i] + carry;//若最后还有进位
    bigIntTrim(result);
}

void bigIntSub1(pBigInt num1, pBigInt num2, pBigInt result) {//异号相减函数
    int i, borrow = 0;//borrow低位的借位

    result->minus = num1->minus;
    for (i = 0; i < num1->digit; i++)    result->num[i] = num1->num[i];
    for (i = 0; i <= num2->digit; i++) {
        result->num[i] = result->num[i] - num2->num[i] - borrow;
        if (result->num[i] < 0) {
            result->num[i] = 10 + result->num[i];
            borrow = 1;
        }
        else borrow = 0;
    }

    if (borrow == 1)    result->num[i] = result->num[i] - borrow;
    i = num1->digit;
    while (i > 0) {
        if (result->num[i] == 0)    i--;
        else break;
    }

    result->digit = i + 1;
    bigIntTrim(result);
}

void bigIntSub(pBigInt num1, pBigInt num2, pBigInt result) {
    num2->minus = -1 * num2->minus;//将减数符号取反
    bigIntAdd(num1, num2, result);
}

void bigIntMul(pBigInt num1, pBigInt num2, pBigInt result) {
    char carry, t;
    int i, j, pos;

    for (i = 0; i < num1->digit + num2->digit; i++)    result->num[i] = 0;//结果数组清零
    for (i = 0; i < num2->digit; i++) {
        carry = 0;//清除进位
        for (j = 0; j < num1->digit; j++) {
            t = num2->num[i] * num1->num[j] + carry;//两个数相乘，加上进位
            carry = t / 10;//进位
            t %= 10;//计算当前位的值
            pos = i + j;//看t应该加在哪个位上
            result->num[pos] += t;
            carry = carry + result->num[pos] / 10;//主要防止num[pos]大于等于10
            result->num[pos] = result->num[pos] % 10;
        }

        if (carry > 0) {
            result->num[i + j] = carry;//加上最高位的进位
            result->digit = i + j + 1;
        }
        else result->digit = i + j;
    }

    result->minus = num1->minus * num2->minus;
}

void bigIntDiv(pBigInt num1, pBigInt num2, pBigInt result, pBigInt residue) {
    bigInt quo1, quo2, residue1;
    int i, j, k, m;//k保存试商结果，m保存商的位数
    char t;

    result->minus = num1->minus * num2->minus;
    residue->num = (char*)malloc(sizeof(char) * (num2->digit + 1));//分配余数空间
    residue->digit = num2->digit + 1;
    for (i = 0; i < residue->digit; i++)    residue->num[i] = 0;//将余数清零
    m = 0;
    for (i = num1->digit - 1; i >= 0; i--) {
        for (j = residue->digit - 1; j > 0; j--) residue->num[j] = residue->num[j - 1];//移余数 (有问题，等会试一下)
        residue->num[0] = num1->num[i];
        bigIntTrim(residue);//整理余数
        k = 0;
        while (bigIntEqual(residue, num2) >= 0) {
            bigIntSub1(residue, num2, residue);
            k++;
        }
        result->num[m++] = k;

    }

    result->digit = m;
    for (i = 0; i < m / 2; i++) {
        t = result->num[i];
        result->num[i] = result->num[m - 1 - i];
        result->num[m - 1 - i] = t;
    }

    bigIntTrim(result);
    bigIntTrim(residue);
}