c++金字塔程序

#include <cstdlib>
#include <iostream>

using namespace std;

#define MAXLEN 40

void printline(int i)
{//i用来指示当前行剩余钻石的个数 
     char cstr[MAXLEN] = {0};
     memset(cstr, '\0', MAXLEN);
     int mid = MAXLEN / 2;
     int j, k;
     
     //初始化，根据奇偶决定是否打印第一行 
     if (i % 2 != 0)
     {
           cstr[mid] = '*';
           j = mid - 2;
           k = mid + 2;
           i --;
     }
     else
     {
           j = mid - 1;
           k = mid + 1;
     }
     
     //从奇数的第二行和偶数的第一行开始，打印算法相同 
     while (i > 0)
     {
           cstr[j] = cstr[k] = '*';
           j -= 2;
           k += 2;
           i -= 2;
     }
     for (int x = 0; x < MAXLEN; x++)
     {
         cout<<cstr[x];
     }
     cout<<endl;
}

int main(int argc, char *argv[])
{
    for (int i = 1; i < 20; i++)
    {
        printline(i);
    }
    system("PAUSE");
    return EXIT_SUCCESS;
}