These puzzles involve simple loops. But now there are a few extra twists, for your puzzle-solving enjoyment.
[E-6]Write a main() program that prints
the odd integers 1 to N, five per line. Write the integers to standard output.
On a Windows machine, this means the integers are written to the DOS window.
Make N a variable in the program and initialize it in an assignment statment
(or read it from user input, if you want.) When N==53, the output
of the program is:
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53
Notice that the last line does not contain a full five integers, but it ends
with "\n" anyway. This will take some extra logic.
Write the program from scratch, or click here for a skeleton: Skeleton.
[E-8]Write a main() program that prints
the odd integers from start down to finish, seven
per line. Make start and finish variables that are
initialized by assignment (or by user input, if you want.) When start==147,
and finish==59, the output of the program is:
147 145 143 141 139 137 135 133 131 129 127 125 123 121 119 117 115 113 111 109 107 105 103 101 99 97 95 93 91 89 87 85 83 81 79 77 75 73 71 69 67 65 63 61 59
The integers that end each line are less regular than in previous programs.
It is probably wise to maintain a separate variable that counts the integers
as they are printed. The last line does not contain the full five integers,
but it ends with "\n" anyway.
Click here for a skeleton: Skeleton.
I would guess that your odds of getting this program correct on the very first try are about one in five. See if you can beat the odds!
[E-8]Write a main() program that prints
the integers from 1 up to 100 that are not multiples of 3 or
5. Print ten integers per line. The output of the program is:
1 2 4 7 8 11 13 14 16 17 19 22 23 26 28 29 31 32 34 37 38 41 43 44 46 47 49 52 53 56 58 59 61 62 64 67 68 71 73 74 76 77 79 82 83 86 88 89 91 92 94 97 98
Click here for a skeleton: Skeleton.
[M-9]Write a main() program that prints
lines for k==0 up to some limit, say k==11.
On each line print those integers from 100*k to 100*k+99 that are multiples of 23. For example, here is the output for k==0 up to k==11:
0 23 46 69 92
115 138 161 184
207 230 253 276 299
322 345 368 391
414 437 460 483
506 529 552 575 598
621 644 667 690
713 736 759 782
805 828 851 874 897
920 943 966 989
1012 1035 1058 1081
1104 1127 1150 1173 1196
This is a fairly tricky program. See if you can get it to work by any means. Once you have some sort of a working program, see if you can improve it. Click here for a skeleton: Skeleton.
Write a main() program that computes and prints N sums: 1, 1+2, 1+2+3, ... , 1+2+3+...+N.
There is a smart way to do this with just one loop,
and a not-so-smart way that uses nested loops.
Try to write the smart way from scratch.
[E-5]Write a main() program that prints
N lines of M stars each, as follows for N==7 M==21:
********************* ********************* ********************* ********************* ********************* ********************* *********************
If you want, ask the user for the value N and M; or else, just hard-wire those values into your program. Here is a skeleton: Skeleton.
[E-7]Write a main() program that prints
n lines. On line j, print j dots, followed by a single
*. For example, for n==15:
* .* ..* ...* ....* .....* ......* .......* ........* .........* ..........* ...........* ............* .............* ..............*
Things are starting to get a little bit tricky. Several things need to be coordinated in this program. Here is a skeleton: Skeleton.
Hard code the value of n, or ask the user.
[E-7]
Write a main() program that
prints a wedge of stars. Print n stars in row 0, (n-1)(n-2)
*************** ************** ************* ************ *********** ********** ********* ******** ******* ****** ***** **** *** ** *
The first star in each line starts in column zero (this is not clear from the above picture.) Here is a skeleton: Skeleton.
[M-8]Write a main() program that prints
a wedge of stars. Print n stars in row 0, (n-1) stars in row 1, (n-2) stars
in row 2, and so on. But now, pad the left side of each line with spaces so
that each line consists of n characters. Here is what this looks like:
***************
**************
*************
************
***********
**********
*********
********
*******
******
*****
****
***
**
*
You will need two loops nested inside of the outer loop. Here is a skeleton: Skeleton.
[M-12]Write a main() program that
prints a triangle of stars. Print 1 star in row 0, 3 stars in row 1, 5 stars
in row 2, and so on. Here is what this looks like:
...........*........... ..........***.......... .........*****......... ........*******........ .......*********....... ......***********...... .....*************..... ....***************.... ...*****************... ..*******************.. .*********************. ***********************
For the non-star characters, use dot or space. Often when debugging programs like this it is useful to print dot instead of space so that it is easier to see what the program did. Here is a skeleton: Skeleton.
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