这个代码的程序要怎么编程

#include <stdio.h>
int main(void)
{
    int k = 0, x = 0, i = 0;
    for (i = 1; i <= 4; i++) //第1至4行
    {
        for (k = 1; k <= 6 - i; k++)
            printf(" ");
        for (x = 1; x <= 2 * i - 1; x++)
            printf("*");
        printf("\n");
    }
    for (i = 3; i >= 1; i--) //第5至7行
    {
        for (k = 1; k <= 6 - i; k++)
            printf(" ");
        for (x = 1; x <= 2 * i - 1; x++)
            printf("*");
        printf("\n");
    }
    return 0;
}