Test: are there three sides of a triangle ?

Sunday, July 4, 2010

 // C08_Ex 9: Input 3 whole number.
// 3 This is an integer form three sides of a triangle or not ?
// If so, what is the triangle?

#include <stdio.h>

void main()
{
    int a, b, c;
    printf("Input 3 whole number: ");
    scanf("%d%d%d", &a, &b, &c);

    if (a + b > c && a + c > b && b + c > a)
    {
        // This is the 3 sides of a triangle
        if (a == b && b == c)
            printf("=> This is an equilateral triangle\n");
        else
        {
            if (a == b || b == c || c == a)
                printf("=> This is an isosceles triangle\n");
            else
            {
                if (a*a + b*b == c*c || b*b + c*c == a*a || c*c + a*a == b*b)
                    printf("=> This is a right triangle\n");
                else
                    printf("=> This is a regular triangle\n");
            }
        }
    }
    else
        printf("=> This is not the three sides of a triangle\n");
}

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Get number of days in month

Friday, July 2, 2010

 // C08_Ex 8: Input month,year
// Output dates of this month

#include <stdio.h>

void main()
{
    int month, yr, result;
  
    printf("Input month,year: ");
    scanf("%d%d", &month, &yr);
  
    if (month>=1 && month<=12)
    {
        switch (month)
        {
        case 1:
        case 3:
        case 5:
        case 7:
        case 8:
        case 10:
        case 12: result = 31; break;
        case 4:
        case 6:
        case 9:
        case 11: result = 30; break;
        case 2:
            if (yr % 400 == 0 || (yr % 4 == 0 && yr % 100 != 0))    //  leap year
                result = 29;
            else
                result = 28;
        }

        printf("=> month %d/%d has %d days\n", month, yr, result);
    }
    else
        printf("=> Invalid month!\n");
}

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Checkout cost of taxi

Tuesday, June 29, 2010

// C08_Ex 7: Checkout cost of taxi from kilometer input. Known:
// First km: 5$
// 2 -> 5 km price: 4$
// 6 km -> price:  3$
// If > 120km , will sale 10%

#include <stdio.h>
#define G1 5
#define G2 4
#define G3 3

void main()
{
    int n;
    float cost;
    printf("Input numbers of km (>0): ");
    scanf("%d", &n);

    if (n == 1)
        cost = G1;
    else
    {
        if (n >= 2 && n <= 5)
            cost = G1 + (n - 1)*G2;
        else
            cost = G1 + 4*G2 + (n - 1 - 4)*G3;
    }

    if (n > 120)
        cost = cost * 0.9;

    printf("=> Total cost: %.2f $\n", cost);
}

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Arranging numbers in ascending order in C

Monday, June 28, 2010

// C08_Ex 6: Input 4 whole number

// To arrange this numbers in order of in ascending

#include <stdio.h>

void main()
{
    int a, b, c, d, tempt;

    printf("Input a, b, c, d: ");
    scanf("%d%d%d%d", &a, &b, &c, &d);
  
    if (a > b) { tempt = a; a = b; b = tempt; }
    if (a > c) { tempt = a; a = c; c = tempt; }
    if (a > d) { tempt = a; a = d; d = tempt; }
    if (b > c) { tempt = b; b = c; c = tempt; }
    if (b > d) { tempt = b; b = d; d = tempt; }
    if (c > d) { tempt = c; c = d; d = tempt; }

    printf("=> After arranging in ascending: %d %d %d %d\n", a, b, c, d);
}

Arranging numbers in ascending order

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Find minimum number

Sunday, June 20, 2010

// C08_Ex 5:Input 4 whole number a, b, c, d
// Find minimum number

#include <stdio.h>

void main()
{
    int a, b, c, d, min, max;
    printf("Input a, b, c, d: ");
    scanf("%d%d%d%d", &a, &b, &c, &d);
  
    min = a;
    if (b < min) min = b;
    if (c < min) min = c;
    if (d < min) min = d;

    printf("=> Minimum number: %d\n", min);

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Solve quadratic equations in C

Friday, June 18, 2010

Today, I tried to translate the very basic "solve quadratic equations" program. I made it while i use C complier of Microsoft : Visual Studio 2005. I have used it since i was a first year student

// C08_Ex 4: To solve quadratic equation: ax^2 + bx + c = 0

#include <stdio.h>
#include <math.h>

void main()
{
    int a, b, c;
    printf("Input a, b, c: ");
    scanf("%d%d%d", &a, &b, &c);
  
    if (a == 0)
    {
        // To solve a simple equation: bx + c = 0
        if (b == 0)
        {
            if (c == 0)
                printf("=> Equation has multitudinous root\n");
            else
                printf("=> Equation has not root\n");
        }
        else
            printf("=> Equation only has a root x = %.2f\n", (float)-c/b);
    }
    else
    {
        double delta = b*b - 4*a*c;

        if (delta < 0)
            printf("=> Equation has not root\n");
        else
        {
            if (delta == 0)
                printf("=> Equation has : x1 = x2 = %.2f\n", (float)-b/(2*a));
            else
            {
                float x1 = (float)(-b - sqrt(delta))/(2*a);
                float x2 = (float)(-b + sqrt(delta))/(2*a);
                printf("=> Equation has 2 root x1 = %.2f, x2 = %.2f\n", x1, x2);
            }
        }
    }
}

 solve quadratic equations in C

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To solve a simple equation in C

Wednesday, June 16, 2010

Whether you are in middle school, high school or even college, you will quickly learn that knowing how to solving equations is essential to any mathematics class. The majority of applications in mathematics will end up in an equation, and you will have to be able to solve that equation in order to answer the original problem. By going over the steps to solving two different linear equations, you will get a better understanding of how they are solved. The two different equations will be in forms ax + b = c and ax - b = c, where a, b and c will be replaced by numeric values and x represents the variable you will be solving for. For the purpose of solve this procedure, the following source code examples will be used: ax+b=0 .

// C08_Ex 3: To solve a simple equation: ax + b = 0

#include <stdio.h>
#include <conio.h>

void main()
{
    int a, b;
    printf("Ipnput a, b: ");
    scanf("%d%d", &a, &b);
  
    if (a == 0)
    {
        if (b == 0)
            printf("=> Equation has multitudinous root\n");
        else
            printf("=> Equation has not root\n");
    }
    else
        printf("=> Equation only has a root: x = %.2f\n", (float)-b/a);
}

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How to convert a lowercase/uppercase character in C ?

Monday, June 14, 2010

C08_Ex 2:  Enter one letter. If it is  uppercase character, changed to lowercase letters, changed back to uppercase.

// Input a character
// If It's a  upper-case character -> change into lower-case character
// If It's a  lower-case character -> change into upper-case character
// Use Visual Studio 2005

#include <stdio.h>

void main()
{
    char ch;
    printf("Input a character: ");
    scanf("%c", &ch);

    if (ch >= 'a' && ch <= 'z')
        ch = ch - 32;
    else
        if (ch >= 'A' && ch <= 'Z')
            ch = ch + 32;

    printf("=> Character after changing: %c\n", ch);
}

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Read a whole number from 1 to 9

C08_Ex 1: Input a  whole number.Reading this whole number with value from 1 to 9.Default, Output:  "Don't know how to read".

// Input a  whole number.
// Reading this whole number with value from 1 to 9.
// Default, output Don't know how to read.
// Use Visual Studio 2005

#include <stdio.h>

void main()
{
    int n;
    printf("Input a  whole number: ");
    scanf("%d", &n);
   
    switch (n)
    {
        case 1: printf("One"); break;
        case 2: printf("Two"); break;
        case 3: printf("Three"); break;
        case 4: printf("Four"); break;
        case 5: printf("Five"); break;
        case 6: printf("Six"); break;
        case 7: printf("Seven"); break;
        case 8: printf("Eight"); break;
        case 9: printf("Nine"); break;
        default: printf("Don't know how to read!");
    }

    printf("\n");
}

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ASCII Chart

Saturday, June 12, 2010

If you a coder, ASCII Chart is so not strange with you. You are a new coder or a student, even professional programmers when you code a program, you often use ASCII Table to solve some problem. In this post I will present some basic definitions about ASCII Chart.

 ASCII - The American Standard Code for Information Interchange is a standard seven-bit code that was proposed by ANSI in 1963, and finalized in 1968. Other sources also credit much of the work on ASCII to work done in 1965 by Robert W. Bemer. ASCII was established to achieve compatibility between various types of data processing equipment. Later-day standards that document ASCII include ISO-14962-1997 and ANSI-X3.4-1986(R1997).

ASCII, pronounced "ask-key", is the common code for microcomputer equipment. The standard ASCII character set consists of 128 decimal numbers ranging from zero through 127 assigned to letters, numbers, punctuation marks, and the most common special characters. The Extended ASCII Character Set also consists of 128 decimal numbers and ranges from 128 through 255 representing additional special, mathematical, graphic, and foreign characters.

Every now and again, I've wished that I had an ASCII chart handy, so I made one and stuck it on this page so that I could find it in a hurry. One thing led to another, and folks started asking me questions about ASCII and other character representations, so I've tried to update this page a bit to answer some of the most common questions. Also, I've added additional info,such as IBM PC Keyboard Scan Codes, and a list of other references.

My ASCII Chart

0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F
0  NUL SOH STX ETX EOT ENQ ACK BEL BS  HT  LF  VT  FF  CR  SO  SI
1  DLE DC1 DC2 DC3 DC4 NAK SYN ETB CAN EM  SUB ESC FS  GS  RS  US
2   SP  !   "   #   $   %   &   '   (   )   *   +   ,   -   .   /
3   0   1   2   3   4   5   6   7   8   9   :   ;   <   =   >   ?
4   @   A   B   C   D   E   F   G   H   I   J   K   L   M   N   O
5   P   Q   R   S   T   U   V   W   X   Y   Z   [   \   ]   ^   _
6   `   a   b   c   d   e   f   g   h   i   j   k   l   m   n   o
7   p   q   r   s   t   u   v   w   x   y   z   {   |   }   ~ DEL

link to decimal-to-ASCII chart.

ASCII Q & A

Every now and then, I get questions about ASCII.
Here are a few:


Q:  What does ASCII stand for?
A:  ASCII stands for American Standard Code for Information Interchange.

Q:  What do CR, LF, SO, and so forth mean?
A:  A more detailed description of the first 32 characters can be found at controlcodes

Q:  Someone wants me to send my resume (or some other file) to them in ASCII, so what do I do?
A:  In general, if somebody asks for your resume or another document "in ASCII", what they really want is a copy of your resume (or whatever the document is) in electronic form, but without any formatting. Save your resume (or other document) from the word processor you're using (such as Microsoft Word ® ) as plain text, and then paste it into an e-mail (or copy it to a floppy disk) and send it to whoever wanted it.

Q:  OK, fine, but how do I save a Microsoft Word ® document as plain text?
A:  Here are some simple instructions for saving a document as plain text in Microsoft Word®. The procedure is similar for other word processors.

1. Click on "File".
2. Select "Save As".
3. In the box marked "Save as type:", select "Text Only (*.txt)" or "Text Only with Line Breaks (*.txt).
4. In the box marked "File name:", enter the file name (a different name than the one that you had been using).
5. Click on the button marked "Save".

If you get a warning indicating that formatting will be lost, don't be alarmed. The whole point of the process is to remove the formatting from the document before you send it.

Q:  I'm writing a program that directly interfaces with the keyboard of an IBM PC, and I need to accept keystrokes for F1, F2, and other keys. What are the IBM PC keyboard codes for F1, F2, and ALT-A, etc?
A:  See IBM PC Keyboard Scan Codes, below
A:  Also, if you're trying to enter CTRL-ALT-DEL to reboot the PC, you might want to try one of my reboot utilities instead.

Q:  What are the ASCII codes for things like the degrees symbol (°), the trademark symbol, solid blocks and other special symbols?
A:  The answer is "it depends". There's really not an ASCII character for most of the special characters (other than those shown in the table at the top of this page. However, there are different extended ASCII sets that include a lot more special characters. (See IBM PC Extended ASCII, below.) Also, for information about including special symbols on a web page, you might look at some of the other charts and references, below.

Q:  How do I generate extended ASCII characters from the keyboard?
A:  DOS will allow you to enter extended ASCII characters into many programs. Here's how you do it:

1. Make sure NumLock is enabled on your keyboard.
2. Press and hold the ALT key.
3. While holding down the ALT key, enter the 3-digit decimal code for the extended ASCII character you want to generate.
4. Release the ALT key.

The trick to this, of course, is knowing the decimal equivalent of the ASCII characters that you want to generate. Since the extended ASCII Chart is in hex, you probably want a guide for to converting hex to decimal.

Q:  Does this work in Windows®?
A:  A better way to enter special symbols in Windows applications (such as Word), is to take advantage of the symbols in the fonts provided by Windows. For example, in Word, use the following steps:

1. Click on "Insert" (in the menu at the top of the page)
2. From the drop-down menu, select "Symbol". A chart of special symbols will appear
3. From the chart, you can select a symbol to insert into your document by highlighting the symbol, and clicking on the word "Insert" at the bottom of the chart.

Q:  What's the ASCII code for CTRL-ALT-DEL, and how do I put it in a DOS batch file?
A:  There's not an easy way to get CTRL-ALT-DEL into a batch file, per se. However, I've created several PC reboot utilities (for both DOS and Windows) that you can try. You can find them on my shareware page.

Q:  What's the ASCII code for CTRL-A, or CTRL-Z?
A:  The value for CTRL-A (^A) is 01. The value for CTRL-Z (^Z), which is often used as an end-of-file marker in DOS is 26 (decimal). All the other CTRL-B through CTRL-Y characters fall in between. (CTRL-B is 2, CTRL-C is 3, and so forth.)

Control Codes

The following is a more detailed description of the first 32 ASCII characters, often referred to as control codes.

NUL (null) SOH (start of heading) STX (start of text) ETX (end of text) EOT (end of transmission) - Not the same as ETB ENQ (enquiry) ACK (acknowledge) BEL (bell) - Caused teletype machines to ring a bell. Causes a beep in many common terminals and terminal emulation programs. BS (backspace) - Moves the cursor (or print head) move backwards (left) one space. TAB (horizontal tab) - Moves the cursor (or print head) right to the next tab stop. The spacing of tab stops is dependent on the output device, but is often either 8 or 10. LF (NL line feed, new line) - Moves the cursor (or print head) to a new line. On Unix systems, moves to a new line AND all the way to the left. VT (vertical tab) FF (form feed) - Advances paper to the top of the next page (if the output device is a printer). CR (carriage return) - Moves the cursor all the way to the left, but does not advance to the next line. SO (shift out) - Switches output device to alternate character set. SI (shift in) - Switches output device back to default character set. DLE (data link escape) DC1 (device control 1) DC2 (device control 2) DC3 (device control 3) DC4 (device control 4) NAK (negative acknowledge) SYN (synchronous idle) ETB (end of transmission block) - Not the same as EOT CAN (cancel) EM (end of medium) SUB (substitute) ESC (escape) FS (file separator) GS (group separator) RS (record separator) US (unit separator)

IBM PC Keyboard Scan Codes

For many of the special key combinations such as ALT-A, F1, PgUp, and so forth, the IBM PC uses a special two-character escape sequence. Depending on the programming language being used and the level at which the keyboard is being accessed, the escape character is either ESC (27, 0x1B), or NUL (0). Here are some common sequences:

Char.  Decimal Pair     Hex Pair    Char.  Decimal Pair    Hex Pair
ALT-A     (00,30)    (0x00,0x1e)    ALT-B    (00,48)    (0x00,0x30)
ALT-C     (00,46)    (0x00,0x2e)    ALT-D    (00,32)    (0x00,0x20)
ALT-E     (00,18)    (0x00,0x12)    ALT-F    (00,33)    (0x00,0x21)
ALT-G     (00,34)    (0x00,0x22)    ALT-H    (00,35)    (0x00,0x23)
ALT-I     (00,23)    (0x00,0x17)    ALT-J    (00,36)    (0x00,0x24)
ALT-K     (00,37)    (0x00,0x25)    ALT-L    (00,38)    (0x00,0x26)
ALT-M     (00,50)    (0x00,0x32)    ALT-N    (00,49)    (0x00,0x31)
ALT-O     (00,24)    (0x00,0x18)    ALT-P    (00,25)    (0x00,0x19)
ALT-Q     (00,16)    (0x00,0x10)    ALT-R    (00,19)    (0x00,0x13)
ALT-S     (00,31)    (0x00,0x1a)    ALT-T    (00,20)    (0x00,0x14)
ALT-U     (00,22)    (0x00,0x16)    ALT-V    (00,47)    (0x00,0x2f)
ALT-W     (00,17)    (0x00,0x11)    ALT-X    (00,45)    (0x00,0x2d)
ALT-Y     (00,21)    (0x00,0x15)    ALT-Z    (00,44)    (0x00,0x2c)
PgUp      (00,73)    (0x00,0x49)    PgDn     (00,81)    (0x00,0x51)
Home      (00,71)    (0x00,0x47)    End      (00,79)    (0x00,0x4f)
UpArrw    (00,72)    (0x00,0x48)    DnArrw   (00,80)    (0x00,0x50)
LftArrw   (00,75)    (0x00,0x4b)    RtArrw   (00,77)    (0x00,0x4d)
F1        (00,59)    (0x00,0x3b)    F2       (00,60)    (0x00,0x3c)
F3        (00,61)    (0x00,0x3d)    F4       (00,62)    (0x00,0x3e)
F5        (00,63)    (0x00,0x3f)    F6       (00,64)    (0x00,0x40)
F7        (00,65)    (0x00,0x41)    F8       (00,66)    (0x00,0x42)
F9        (00,67)    (0x00,0x43)    F10      (00,68)    (0x00,0x44)
F11       (00,133)   (0x00,0x85)    F12      (00,134)   (0x00,0x86)
ALT-F1    (00,104)   (0x00,0x68)    ALT-F2   (00,105)   (0x00,0x69)
ALT-F3    (00,106)   (0x00,0x6a)    ALT-F4   (00,107)   (0x00,0x6b)
ALT-F5    (00,108)   (0x00,0x6c)    ALT-F6   (00,109)   (0x00,0x6d)
ALT-F7    (00,110)   (0x00,0x6e)    ALT-F8   (00,111)   (0x00,0x6f)
ALT-F9    (00,112)   (0x00,0x70)    ALT-F10  (00,113)   (0x00,0x71)
ALT-F11   (00,139)   (0x00,0x8b)    ALT-F12  (00,140)   (0x00,0x8c)

 
Hint - If you look at how the keys are laid out on the keyboard, you'll probably see the pattern.

IBM PC Extended ASCII Display Characters

Strictly speaking, the ASCII character set only includes values up to 127 decimal (7F hex). However, when the IBM PC was developed, the video card contained one byte for each character in the 80x25 character display. Gee...what to do with that extra bit per character? Why not invent 128 new characters, for line-drawing and special symbols? The result, of course, was the extended ASCII character set for the IBM PC. The chart below shows (most of) the characters that can be generated by the display in the original IBM PC.

 Microsoft Windows ® has a different notion about what the high-order (upper 128) characters are, as shown in the table below.

Converting Hex to Decimal

Here's a chart that shows the conversion between hex and decimal.

    0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F.
0  000 001 002 003 004 005 006 007 008 009 010 011 012 013 014 015
1  016 017 018 019 020 021 022 023 024 025 026 027 028 029 030 031
2  032 033 034 035 036 037 038 039 040 041 042 043 044 045 046 047
3  048 049 050 051 052 053 054 055 056 057 058 059 060 061 062 063
4  064 065 066 067 068 069 070 071 072 073 074 075 076 077 078 079
5  080 081 082 083 084 085 086 087 088 089 090 091 092 093 094 095
6  096 097 098 099 100 101 102 103 104 105 106 107 108 109 110 111
7  112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127
8  128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143
9  144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159
A  160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175
B  176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191
C  192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207
D  208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223
E  224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239
F  240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255

 
If you're having trouble getting the hang of the above chart, here's a hint:
Hex 41 (written as 0x41 in the programing language C) is equivalent to decimal 65.

Converting Hex to Octal

Here's a chart that shows the conversion between hex and octal.

    0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F.
0  000 001 002 003 004 005 006 007 010 011 012 013 014 015 016 017
1  020 021 022 023 024 025 026 027 030 031 032 033 034 035 036 037
2  040 041 042 043 044 045 046 047 050 051 052 053 054 055 056 057
3  060 061 062 063 064 065 066 067 070 071 072 073 074 075 076 077
4  100 101 102 103 104 105 106 107 110 111 112 113 114 115 116 117
5  120 121 122 123 134 125 126 127 130 131 132 133 134 135 136 137
6  140 141 142 143 144 145 146 147 150 151 152 153 154 155 156 157
7  160 161 162 163 164 165 166 167 170 171 172 173 174 175 176 177
8  200 201 202 203 204 205 206 207 210 211 212 213 214 215 216 217
9  220 221 222 223 224 225 226 227 230 231 232 233 234 235 236 237
A  240 241 242 243 244 245 246 247 250 251 252 253 254 255 256 257
B  260 261 262 263 264 265 266 267 270 271 272 273 274 275 276 277
C  300 301 302 303 304 305 306 307 310 311 312 313 314 315 316 317
D  320 321 322 323 324 325 326 327 330 331 332 333 334 335 336 337
E  340 341 342 343 344 345 346 347 350 351 352 353 354 355 356 357
F  360 361 362 363 364 365 366 367 370 371 372 373 374 375 376 377

If you're having trouble getting the hang of the above chart, here's a hint:
Hex 41 (written as 0x41 in the programing language C) is equivalent to octal 101.

 link to decimal-to-ASCII chart.

Other ASCII Charts

Here are some other folks' ASCII charts, and other interesting ASCII-related references.

ISO 646

ASCII Table.Com - The Q and A looks familiar, doesn't it?

ASCII - ISO 8859-1 Table

HTML Character Entities

Decimal ASCII for HTML

EBCDIC Character Set - Not ASCII at all

BAUDOT - Another Set of Character Codes

More on BAUDOT

Brief History of Character Codes - Good reference material!

A Bit about Braille - Includes info about dotless Braille.

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