# Hello World Program in Bash Shell

#echo "Hello World!"
echo "Ashraful Islam"
echo "Enter a number: "
read N
echo $N
echo "$N"
echo "You Entered : $N"

#echo "Enter another number: "
#read M
#echo $M
#echo "$M"
#echo "You Entered : $M"


VAR1=17
VAR2=19
VAR3=20

V=`expr $N + $VAR2`
echo $V


echo "Values of the Variables: "
echo $VAR1
echo $VAR2
echo $VAR3

VAR4=`expr $VAR1 + $VAR2`
echo "$VAR1 + $VAR2 = $VAR4"

VAR4=`expr $VAR1 * $VAR2`
echo "$VAR1 * $VAR2 = $VAR4"

A[0]=77
A[1]=78
A[2]=79
echo $A[0]
echo $A[1]
echo $A[2]

echo ${A[0]}
echo ${A[1]}
echo ${A[2]}

B=(44 45 46 47 48)
echo ${B[0]}
echo ${B[1]}
echo ${B[2]}

New=`expr ${B[3]} + ${B[4]}`
echo $New

echo "Greater number between Variable 1 & Variable 2: "
if [ $VAR1 -gt $VAR2 ]
then
    echo "$VAR1 is greater"
else
    echo "$VAR2 is greater"
fi


echo "Greater number among Variable 1 , Variable 2 & Variable 3: "
if [ $VAR1 -gt $VAR2 ]
then
    if [ $VAR1 -gt $VAR3 ]
    then 
        echo "$VAR1 is greater"
    else
        echo "$VAR3 is greater"
    fi
else
    if [ $VAR2 -gt $VAR3 ]
    then 
        echo "$VAR2 is greater"
    else
        echo "$VAR3 is greater"
    fi
fi


echo "Smallest number among Variable 1 , Variable 2 & Variable 3 of Array B: "
if [ ${B[0]} -lt ${B[1]} ]
then
    if [ ${B[0]} -lt ${B[2]} ]
    then 
        echo "${B[0]} is smallest"
    else
        echo "${B[2]} is smallest"
    fi
else
    if [ ${B[1]} -lt ${B[2]} ]
    then 
        echo "${B[1]} is smallest"
    else
        echo "${B[2]} is smallest"
    fi
fi


NUMBER=10
while [ $NUMBER -gt 0 ]
do
    echo $NUMBER
    NUMBER=$((NUMBER-1))
done

NUMBER1=10
while [ $NUMBER1 -ge 0 ]
do
    echo $NUMBER1
    NUMBER1=$((NUMBER1-1))
done

i=1
NUMBER2=10
while [ $i -lt $NUMBER2 ]
do
    echo $i
    i=$((i+1))
done

sum=0
for((j=1;j<=$NUMBER2;j++))
{
    sum=$((sum+j))
}
echo "Sum of the given sequence = $sum"


sum_ID=0
ID=(1 9 1 1 5 1 2 1 7 3)
echo "Sum of the digits of ID: "
for((k=0;k<10;k++))
{
    sum_ID=`expr $sum_ID + ${ID[k]}`
}
echo $sum_ID

sum_ID1=0
m=0
while [ $m -lt 10 ]
do
    sum_ID1=`expr $sum_ID1 + ${ID[m]}`
    m=`expr $m + 1`
done
echo "Sum of the digits of ID: $sum_ID1"