请问各位路过的大佬：我这段代码哪里有错，结果一直不成功！？

#include <iostream>
#include <math.h>
using namespace std;
const int NMAX = 1024;
int multiplicationOfLargeNumbers(int x,int y){//计算两大数的乘积
int X[NMAX],Y[NMAX];//分别用来储存两大数的裂项 memset(X,0,NMAX);
memset(Y,0,NMAX);
int xNumbers = 0; while (x){//将x的裂项存入X数组中
X[xNumbers] = (x%10)*(int)pow(10,(double)xNumbers);
x /= 10;
xNumbers++;
}
int yNumbers = 0;
while (y){//将y的裂项存入Y数组中
Y[yNumbers] = (x%10)*(int)pow(10,(double)yNumbers);
y /= 10;
yNumbers++;
}
int product;//两数之积
for (int i = 0;i <= xNumbers;i++){
for (int j = 0;j <= yNumbers;j++){ product += X[i]*Y[j];
}
}
return product;
}
int main(){
int a = 0,b = 0;
printf("%s\n","请输入两个大数："); scanf("%d%d",&a,&b); printf("%d\n",multiplicationOfLargeNumbers(a,b));//调用函数
return 0;
}