多层for循环之显示图形

一、直线

#!/bin/bash
for ((i=1;i<=20;i++))
    do
    echo -n "*"
    done
echo ""

二、9*9乘法口径表

#!/bin/bash
for ((a=1;a<=9;a++))
    do
    for ((b=1;b<=$a;b++))
    do
    c=$[$b * $a]
    echo -n -e "$b*$a=$c\t"
    done
    echo ""
done

三、矩形

#!/bin/bash
for ((a=1;a<=10;a++))
    do
    for ((b=1;b<=5;b++))
    do
    echo -n "*"
    done
    echo ""
done

四、三角形

1. 直角三角形

#!/bin/bash
for ((i=1;i<=10;i++))
    do
    for ((j=1;j<=$i;j++))
        do
        echo -n "*"
    done
    echo ""
done

#!/bin/bash
for ((i=1;i<=10;i++))
    do
    for ((j=10;j>=$i;j--))
        do
        echo -n " "
    done
    for ((k=1;k<=$i;k++))
        do
        echo -n "*"
    done
    echo ""
done

#!/bin/bash
for ((i=1;i<=10;i++))
    do
    for ((j=10;j>=$i;j--))
        do
        echo -n "*"
    done
    echo ""
done

#!/bin/bash
for ((i=1;i<=10;i++))
    do
    for ((j=1;j<=$i;j++))
        do
        echo -n " "
    done
    for ((k=10;k>=$i;k--))
        do
        echo -n "*"
    done
    echo ""
done

2. 等腰三角形

#!/bin/bash
for ((i=1;i<=10;i++))
    do
    for ((j=10;j>=$i;j--))
        do
        echo -n " "
    done
    for ((k=1;k<=$i;k++))
        do
        echo -n "*"
    done
    for ((l=2;l<=$i;l++))
        do
        echo -n "*"
    done
    echo ""
done

#!/bin/bash
for ((i=1;i<=10;i++))
    do
    for ((j=1;j<=$i;j++))
        do
        echo -n " "
    done
    for ((k=10;k>=$i;k--))
        do
        echo -n "*"
    done
    for ((l=9;l>=$i;l--))
        do
        echo -n "*"
    done
    echo ""
done

五、菱形

#!/bin/bash
for ((a=1;a<=9;a++))
    do
    for ((b=10;b>=$a;b--))
        do
        echo -n " "
    done
    for ((c=1;c<=$a;c++))
        do
        echo -n "*"
    done
    for ((d=2;d<=$a;d++))
        do
        echo -n "*"
    done
    echo ""
done

for ((e=1;e<=10;e++))
    do
    for ((f=1;f<=$e;f++))
        do
        echo -n " "
    done
    for ((g=10;g>=$e;g--))
        do
        echo -n "*"
    done
    for ((h=9;h>=$e;h--))
        do
        echo -n "*"
    done
    echo ""
done

六、等腰梯形

#!/bin/bash
for ((i=1;i<=10;i++))
    do
    for ((j=10;j>=$i;j--))
        do
        echo -n " "
    done
    for ((k=1;k<=$i;k++))
        do
        echo -n "*"
    done
    for ((m=1;m<=8;m++))
        do
        echo -n "*"
    done
    for ((n=1;n<=$i;n++))
        do
        echo -n "*"
    done
    echo ""
done