[c] pyramids for CS1010

pyramid.c

#include <malloc.h>
#include <string.h>
void print_pyramid(int k)
{
        int i;
        size_t sz = 1 + (k-1)*2;
        char *buf = malloc(sizeof(char) * sz);
        memset(buf, '*', sz);
        for (i = 1; i < k; i++)
                printf("%*.*s\n", k + i - 1, 1 + (i-1) * 2, buf);
        printf("%.*s\n", sz, buf);
}