Star Code

#include <iostream>
#include <memory>
using namespace std;

int* multi(int* num1, int size1, int* num2, int size2)
{
	int size = size1 + size2;
	int* ret = new int[size];
	int i = 0;
	memset(ret, 0, sizeof(int)*size);
	//先把两数组分别相乘 
	for(i = 0; i < size2; ++i)
	{
		int k = i;
		for(int j = 0; j < size1; ++j)
		{
			ret[k++] += num2[i]*num1[j];
		}
	}
	//进位 
	for(i = 0; i < size; ++i)
	{
		if(ret[i] >= 10)
		{
			//加上进位 
			ret[i+1] += ret[i] / 10;
			//只留个位 
			ret[i] %= 10;
		}
	}
	return ret;
}
int main(int argc, char *argv[])
{
	int num1[] = {1,2,3,4,5,6,7,8,9,1,1,1,1,1};
	int num2[] = {1,1,1,2,2,2,3,3,3,4,4,4,5,5};
	int* ret = multi(num1, 14, num2, 14);
	for(int i = 27; i >= 0; i--)
	{
		cout << ret[i];
	}
	delete[] ret;
	return 0;
}

计算11111987654321*55444333222111=616096746266157102781891631

void duff_memcpy(char* to, char* from, size_t count)
{
    size_t n = (count+7) / 8;
    switch(count % 8) 
	{
    case 0: do{ *to++ = *from++;
    case 7:     *to++ = *from++;
    case 6:     *to++ = *from++;
    case 5:     *to++ = *from++;
    case 4:     *to++ = *from++;
    case 3:     *to++ = *from++;
    case 2:     *to++ = *from++;
    case 1:     *to++ = *from++;
    		}while(--n>0);
    }
} 

/*ConvertToPY v0.1 author:star date:2010-02-25 */
#include <iostream> 
#include <string> 

using namespace std; 
static char convert(wchar_t n);
static bool In(wchar_t start, wchar_t end, wchar_t code);

int main(int argc, char* argv[]) 
{
	string sChinese = "取得拼音的首字母"; //   输入的字符串
	char chr[3]; 
	wchar_t wchr = 0; 
	char* buff = new char[sChinese.length()/2]; 
 
	memset(buff, 0, sizeof(char)*sChinese.length()/2+1); 
	for (int i = 0, j = 0; i < (sChinese.length()/2); ++i) 
	{   
		memset(chr, 0, sizeof(chr)); 
		chr[0]  = sChinese[j++]; 
		chr[1]  = sChinese[j++]; 
		chr[2]  = '\0'; 
		wchr    = 0; 
		wchr    = (chr[0] & 0xff) << (1<<3); 
		wchr   |= (chr[1] & 0xff); 
		buff[i] = convert(wchr); 
	} 
	cout << "结果 ：[" << buff << "]" << endl; 
	return 0; 
} 
char convert(wchar_t n) 
{  
	if (In(0xB0A1,0xB0C4,n)) return 'A'; 
	if (In(0XB0C5,0XB2C0,n)) return 'B'; 
	if (In(0xB2C1,0xB4ED,n)) return 'C'; 
	if (In(0xB4EE,0xB6E9,n)) return 'D'; 
	if (In(0xB6EA,0xB7A1,n)) return 'E'; 
	if (In(0xB7A2,0xB8c0,n)) return 'F'; 
	if (In(0xB8C1,0xB9FD,n)) return 'G'; 
	if (In(0xB9FE,0xBBF6,n)) return 'H'; 
	if (In(0xBBF7,0xBFA5,n)) return 'J'; 
	if (In(0xBFA6,0xC0AB,n)) return 'K'; 
	if (In(0xC0AC,0xC2E7,n)) return 'L'; 
	if (In(0xC2E8,0xC4C2,n)) return 'M'; 
	if (In(0xC4C3,0xC5B5,n)) return 'N'; 
	if (In(0xC5B6,0xC5BD,n)) return 'O'; 
	if (In(0xC5BE,0xC6D9,n)) return 'P'; 
	if (In(0xC6DA,0xC8BA,n)) return 'Q'; 
	if (In(0xC8BB,0xC8F5,n)) return 'R'; 
	if (In(0xC8F6,0xCBF0,n)) return 'S'; 
	if (In(0xCBFA,0xCDD9,n)) return 'T'; 
	if (In(0xCDDA,0xCEF3,n)) return 'W'; 
	if (In(0xCEF4,0xD188,n)) return 'X'; 
	if (In(0xD1B9,0xD4D0,n)) return 'Y'; 
	if (In(0xD4D1,0xD7F9,n)) return 'Z'; 
	return 0; 
} 
inline bool In(wchar_t start, wchar_t end, wchar_t code) 
{  
	if (code >= start && code <= end) 
		return true; 
	return false; 
}