程序代码：

# include <stdio.h>

int main(void)

{
    int k, i, j, x;
   
    printf("请输入一个数:");
   
    scanf("%d",&x);
    for (i = 0;i<=(x-4); i++)
    {
        for (k = 1;k <= i; k++)
            printf(" ");
        for (j = 0;j<x-i*2; j++)
            printf("*");

        printf("\n");
    }
      
    return 0;
}

程序代码：

#include "stdafx.h"
#include <iostream>

using std::cout;
using std::cin;
using std::endl;

int _tmain(int argc, _TCHAR* argv[])
{
    int iLength;
    int iCount;
    int iLine;

    while (true)
    {
        cout << "请输入金字塔底的砖头数(0-40, 0结束程序): ";
        cin >> iLength;
        if (iLength < 0 || iLength > 40)
        {
            continue;
        }
        if (iLength == 0)
        {
            break;
        }
        iLine = 0;
        while (iLength > 0)
        {
            iLine++;
            for (iCount = 0; iCount < iLine; iCount++)
            {
                cout << ' ';
            }
            for (iCount = iLength; iCount > 0; iCount--)
            {
                cout << '*';
            }
            cout << endl;
            iLength -= 2;
        }
    }

    return 0;
}