alternate_number_series_v1.c

/*
    alternate_number_series_v1.c

    Write a c Program that will print the number series vertically on screen:

    10 1 9 2 8 3 7 4 6 5

    There, two series of numbers appear alternately

    first 10 9 8 7 6

    and second 1 2 3 4 5.

There is no difference between loops in C,
except that the do-while loop must be performed at least once.


for loop
https://www.tutorialspoint.com/cprogramming/c_for_loop.htm

for ( init; condition; increment ) {
   statement(s);
}


while loop
https://www.tutorialspoint.com/cprogramming/c_while_loop.htm

init;
while(condition) {
   statement(s);
   increment;
}


do-while loop
https://www.tutorialspoint.com/cprogramming/c_do_while_loop.htm

init;
do {
   statement(s);
   increment;
} while( condition );


    You can find all my C programs at Dragan Milicev's pastebin:

    https://pastebin.com/u/dmilicev

*/

#include <stdio.h>

int main(void)
{
    int i, j, number_of_pairs=5;

    printf("\n Using for loop, the first way \n\n");
    for( i=0; i<number_of_pairs; i++ )
        printf(" %2d \n %2d \n", 10-i, i+1 );

    printf("\n Using for loop, the second way \n\n");
    for( i=10,j=1; j<=number_of_pairs; i--,j++ )
        printf(" %2d \n %2d \n", i, j );

    printf("\n Using while loop \n\n");
    i=10;                               // initial values
    j=1;
    while(j<=number_of_pairs)           // condition
    {
        printf(" %2d \n %2d \n", i, j );
        i--;                            // decrement
        j++;                            // increment
    }

    printf("\n Using do-while loop \n\n");
    i=10;                               // initial values
    j=1;
    do
    {
        printf(" %2d \n %2d \n", i, j );
        i--;                            // decrement
        j++;                            // increment
    } while(j<=number_of_pairs);        // condition


    return 0;
}