“数星星”

学过编程的朋友都知道，当初为了学习编程语言中的各种语法结构，我们要试着解决各种各样奇怪的题目。其中"数星星"就似乎其中的一种。什么是"数星星"呢？就是打印各种形状的"*"，正三角、倒三角、菱形等等。本篇博客纯粹为了纪念我们逝去的岁月。

a）正三角

void star_1()
{
    int outer;
    int inner;

    for(outer = 1; outer <10; outer ++){
        for(inner = 1; inner <= outer; inner ++){
            printf("%c ", '*');
        }
        printf("n");
    }
}

b）倒三角

void star_2()
{
    int outer;
    int inner;

    for(outer = 9; outer >= 1; outer --){
        for(inner = 1; inner <= outer; inner ++){
            printf("%c ", '*');
        }
        printf("n");
    }
}

c）左三角

void star_3()
{
    int outer;
    int inner;

    for(outer = -4; outer <= 4; outer ++){
        for(inner = 1; inner <= (5 - abs(outer)); inner ++){
            printf("*");
        }

        for(; inner <= 5; inner ++){
            printf(" ");
        }

        printf("n");
    }
}

d） 右三角

void star_4()
{
    int outer;
    int inner;

    for(outer = -4; outer <= 4; outer ++){
        for(inner = 1; inner <= abs(outer); inner ++){
            printf(" ");
        }

        for(; inner <= 5; inner ++){
            printf("*");
        }

        printf("n");
    }
}

e）垂直菱形

void star_5()
{
    int outer;
    int inner;

    for(outer = -4; outer <= 4; outer ++){
        for(inner = -4; inner <= abs(outer) -5; inner ++){
            printf(" ");
        }

        for(; inner <= 5 - abs(outer); inner ++){
            printf("*");
        }

        printf("n");
    }
}

f）水平菱形

void star_6()
{
    int outer;
    int inner;

    for(outer = -9; outer <= 0; outer ++){
        for(inner = outer; inner < 0; inner ++){
            printf(" ");
        }

        for(; inner <= 9; inner ++){
            printf("*");
        }

        printf("n");
    }
}

g）杨辉三角形

void star_7()
{
    int outer;
    int inner;

    for(outer = 1; outer <10; outer ++){
        for(inner = 1; inner <= outer; inner ++){
            printf("%3d ", outer * inner);
        }
        printf("n");
    }
}