tree.c

#include<stdlib.h>
#include<stdio.h>
#include<math.h>

#define MIN_STEM_HEIGHT 1
#define MIN_STEM_WIDTH 1


int main(int argc, char** argv) {

    int crownHeight = (argc < 2) ? 10 : atoi(argv[1]);

    int i, j;

    for (i = 0; i < crownHeight; ++i)
    {
        for (j = 0; j < (crownHeight - i - 1); ++j)
        {
            printf(" ");
        }
        printf("o");
        for (j = 0; j < i; ++j)
        {
            printf("oo");
        }
        printf("\n");
    }

    int stemHeight = (int)(crownHeight * 0.20 + 0.5);
    if (stemHeight < MIN_STEM_HEIGHT)
    {
        stemHeight = MIN_STEM_HEIGHT;
    }

    int stemWidth = (int)((crownHeight * 2 - 1) * 0.10 + 0.5);
    if (stemWidth < MIN_STEM_WIDTH)
    {
        stemWidth = MIN_STEM_WIDTH;
    }

    for (i = 0; i < stemHeight; ++i)
    {
        for (j = 0; j < (crownHeight - stemWidth - 1); ++j)
        {
            printf(" ");
        }
        printf("#");
        for (j = 0; j < stemWidth; ++j)
        {
            printf("##");
        }
        printf("\n");
    }

    return 0;
}