//大数据相乘,具体的算法思想见c
#define _CRT_SECURE_NO_WARNINGS //vs2013去掉安全检查
#include <stdlib.h>
#include <string.h>
#include <iostream>
using namespace std;
class big_data
{
public:
void init_string()
{
cout << "str1 = ";
cin >> str1;
cout << endl;
cout << "str2 = ";
cin >> str2;
cout << endl;
}
char* big_data_multi ()
{
int length_str1 = strlen(str1);
int length_str2 = strlen(str2);
int *pstr3 = (int*)malloc(sizeof(int)*(length_str1+length_str2));
memset(pstr3, 0, sizeof(int)*(length_str1+length_str2));//一定要初始化,否则乱码
for(int i = 0; i < length_str2; i++)//循环累乘相加
{
for(int j = 0; j < length_str1; j++)
{
pstr3[i + j + 1] += (str1[j] - '0') * (str2[i] - '0');
}
}
for (int i = length_str1 + length_str2 - 1; i >= 0; i--)
{
if(pstr3[i] >= 10)
{
pstr3[i - 1] += pstr3[i] / 10;
pstr3[i] = pstr3[i]%10;
}
}
int i = 0;
while (pstr3[i] == 0)
{
i++;
}
char *pstr4 = (char*)malloc(sizeof(char)*(length_str1 + length_str2 + 1));
int j = 0;
for(; j < length_str1+length_str2 && i < length_str1+length_str2; j++,i++)
{
pstr4[j] = pstr3[i] + '0';
}
pstr4[j] = '