| 01_hello.c | Download |
|---|---|
#include <stdio.h>
int main()
{
printf( "hello, world\n" );
}
/*
Discuss:
- compilation
(Windows)
- MinGW (http://www.mingw.org/)
- SCITE setup (http://www.scintilla.org/SciTE.html)
(installer: http://gisdeveloper.tripod.com/scite.html)
"Options" --> "Open cpp properties"
Change line from:
cc=g++ -pedantic -Os -fno-exceptions -c $(FileNameExt) -o $(FileName).o
to:
cc=gcc -pedantic -Os -fno-exceptions $(FileNameExt) -o $(FileName).exe
- C program: functions & variables
- main: special - program begins executing
- character string (string constant)
- \n - escape sequence
- printf: formatted print
- see 02_hello.c
Exercises (page 8)
*/
|
|
| 01_hello.c | Download |
| 02_hello.c | Download |
|---|---|
#include <stdio.h>
main()
{
printf("hello, ");
printf("world");
printf("\n");
}
|
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| 02_hello.c | Download |
| 03_tempconv.c | Download |
|---|---|
#include <stdio.h>
/* print Fahrenheit-Celsius table
for fahr = 0, 20, ..., 300 */
main()
{
int fahr, celsius;
int lower, upper, step;
lower = 0; /* lower limit of temperature scale */
upper = 300; /* upper limit */
step = 20; /* step size */
fahr = lower;
while (fahr <= upper) {
celsius = 5 * (fahr-32) / 9;
printf("%d\t%d\n", fahr, celsius);
fahr = fahr + step;
}
}
/*
Discuss:
- comments
- declarations (types)
- variables
- arithmetic expressions
- loops
- formatted output
- types:
basic data types (int, float, char, short, long, double)
arrays
structs
unions
pointers to above
functions that return above
- indentation, braces
- see 04_tempconv.c, 05_tempconv.c
Exercises (page 13): 1.4
*/
|
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| 03_tempconv.c | Download |
| 04_tempconv.c | Download |
|---|---|
#include <stdio.h>
/* print Fahrenheit-Celsius table
for fahr = 0, 20, ..., 300; floating-point version */
main()
{
float fahr, celsius;
float lower, upper, step;
lower = 0; /* lower limit of temperatuire scale */
upper = 300; /* upper limit */
step = 20; /* step size */
fahr = lower;
while (fahr <= upper) {
celsius = (5.0/9.0) * (fahr-32.0);
printf("%3.0f %6.1f\n", fahr, celsius);
fahr = fahr + step;
}
}
|
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| 04_tempconv.c | Download |
| 05_tempconv.c | Download |
|---|---|
#include <stdio.h>
/* print Fahrenheit-Celsius table */
main()
{
int fahr;
for (fahr = 0; fahr <= 300; fahr = fahr + 20)
printf("%3d %6.1f\n", fahr, (5.0/9.0)*(fahr-32));
}
/*
Discuss:
- for statement
- see 06_tempconv.c
Exercise 1-5 (page 14)
*/
|
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| 05_tempconv.c | Download |
| 06_tempconv.c | Download |
|---|---|
#include <stdio.h>
#define LOWER 0 /* lower limit of table */
#define UPPER 300 /* upper limit */
#define STEP 20 /* step size */
/* print Fahrenheit-Celsius table */
main()
{
int fahr;
for (fahr = LOWER; fahr <= UPPER; fahr = fahr + STEP)
printf("%3d %6.1f\n", fahr, (5.0/9.0)*(fahr-32));
}
/*
Discuss:
- symbolic constants
*/
|
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| 06_tempconv.c | Download |
| 07_copy.c | Download |
|---|---|
#include <stdio.h>
/* copy input to output; */
main()
{
int c;
c = getchar();
while (c != EOF) {
putchar(c);
c = getchar();
}
}
/*
Discuss:
- getchar(): reads next input character from text stream
- why returns int? (not char)
- see 08_copy.c
*/
|
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| 07_copy.c | Download |
| 08_copy.c | Download |
|---|---|
#include <stdio.h>
/* copy input to output; */
main()
{
int c;
while ((c = getchar()) != EOF)
putchar(c);
}
/*
Discuss:
- assignment is an expression (value is value of lhs after assigment)
- common loop idiom (parentheses needed b/c of precedence)
- c = getchar() != EOF <===> c = (getchar() != EOF)
why returns 0 or 1?
Exercise 1-7 (page 17)
*/
|
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| 08_copy.c | Download |
| 09_count.c | Download |
|---|---|
#include <stdio.h>
/* count characters in input; */
main()
{
long nc;
nc = 0;
while (getchar() != EOF)
++nc;
printf("%ld\n", nc);
}
/*
Discuss:
- ++, --, post-/pre-
- change long to double, printf( "%.0f...
for (nc = 0; getchar() != EOF; ++nc)
;
empty loop body
*/
|
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| 09_count.c | Download |
| 10_countline.c | Download |
|---|---|
#include <stdio.h>
/* count lines in input */
main()
{
int c, nl;
nl = 0;
while ((c = getchar()) != EOF)
if (c == '\n')
++nl;
printf("%d\n", nl);
}
/*
Discuss:
- counting lines = counting newline characters
- == (equality operator), no warning/error if use = instead!
- character constants
integer value equal to numerical value in machine's
character set (e.g. ASCII)
if (c == 10) ... (same thing...)
Exercises 1-8, 1-9, 1-10 (page 20)
*/
|
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| 10_countline.c | Download |
| 11_countword.c | Download |
|---|---|
#include <stdio.h>
#define IN 1 /* inside a word */
#define OUT 0 /* outside a word */
/* count lines, words, and characters in input */
main()
{
int c, nl, nw, nc, state;
state = OUT;
nl = nw = nc = 0;
while ((c = getchar()) != EOF) {
++nc;
if (c == '\n')
++nl;
if (c == ' ' || c == '\n' || c == '\t')
state = OUT;
else if (state == OUT) {
state = IN;
++nw;
}
}
printf("%d %d %d\n", nl, nw, nc);
}
/*
Discuss:
- UNIX program wc
- nl = nw = nc = 0 <===> nl = (nw = (nc = 0));
- || ==> 'OR', && ==> 'AND'
- else statement
Exercises 1-11, 1-12 (page 21)
*/
|
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| 11_countword.c | Download |
| 12_countdigit.c | Download |
|---|---|
#include <stdio.h>
/* count digits, white space, others */
main()
{
int c, i, nwhite, nother;
int ndigit[10];
nwhite = nother = 0;
for (i = 0; i < 10; ++i)
ndigit[i] = 0;
while ((c = getchar()) != EOF)
if (c >= '0' && c <= '9')
++ndigit[c-'0'];
else if (c == ' ' || c == '\n' || c == '\t')
++nwhite;
else
++nother;
printf("digits =");
for (i = 0; i < 10; ++i)
printf(" %d", ndigit[i]);
printf(", white space = %d, other = %d\n",
nwhite, nother);
}
/*
Discuss:
- arrays, subscripts
- else if
- testing for digits
*/
|
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| 12_countdigit.c | Download |
| 13_power.c | Download |
|---|---|
#include <stdio.h>
int power(int m, int n);
/* test power function */
main()
{
int i;
for (i = 0; i < 10; ++i)
printf("%d %d %d\n", i, power(2,i), power(-3,i));
return 0;
}
/* power: raise base to n-th power; n >= 0 */
int power(int base, int n)
{
int i, p;
p = 1;
for (i = 1; i <= n; ++i)
p = p * base;
return p;
}
/*
Discuss:
- functions (encapsulate computations, use without worry about implem.)
- function declaration (function prototype), definition
- parameter vs. argument (formal argument/actual argument)
- arguments, call by value
- local variables
- call by reference using pointers (later), arrays are call by reference
change power:
int p;
for (p=1; n>0; --n)
p = p * base;
return p;
Exercise 1-15 (page 27)
*/
|
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| 13_power.c | Download |
| 14_longline.c | Download |
|---|---|
#include <stdio.h>
#define MAXLINE 1000 /* maximum input line length */
int getline(char line[], int maxline);
void copy(char to[], char from[]);
/* print the longest input line */
main()
{
int len; /* current line length */
int max; /* maximum length seen so far */
char line[MAXLINE]; /* current input line */
char longest[MAXLINE]; /* longest line saved here */
max = 0;
while ((len = getline(line, MAXLINE)) > 0)
if (len > max) {
max = len;
copy(longest, line);
}
if (max > 0) /* there was a line */
printf("%s", longest);
return 0;
}
/* getline: read a line into s, return length */
int getline(char s[],int lim)
{
int c, i;
for (i=0; i < lim-1 && (c=getchar())!=EOF && c!='\n'; ++i)
s[i] = c;
if (c == '\n') {
s[i] = c;
++i;
}
s[i] = '\0';
return i;
}
/* copy: copy 'from' into 'to'; assume to is big enough */
void copy(char to[], char from[])
{
int i;
i = 0;
while ((to[i] = from[i]) != '\0')
++i;
}
/*
Discuss:
- character arrays (most common use of arrays)
- pseudocode
while (there's another line)
if (it's longer than previous longest)
save it
save its length
print longest line
- getline() - fetch next line of input,
copy() - to copy new line to save it
- strings and null character '\0' terminator
Exercise 1-16, 1-18
*/
|
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| 14_longline.c | Download |
| 15_longline.c | Download |
|---|---|
#include <stdio.h>
#define MAXLINE 1000 /* maximum input line size */
/* external variables */
int max; /* maximum length seen so far */
char line[MAXLINE]; /* current input line */
char longest[MAXLINE]; /* longest line saved here */
int getline(void);
void copy(void);
/* print longest input line; specialized version */
main()
{
int len;
extern int max;
extern char longest[];
max = 0;
while ((len = getline()) > 0)
if (len > max) {
max = len;
copy();
}
if (max > 0) /* there was a line */
printf("%s", longest);
return 0;
}
/* getline: specialized version */
int getline(void)
{
int c, i;
extern char line[];
for (i = 0; i < MAXLINE - 1
&& (c=getchar()) != EOF && c != '\n'; ++i)
line[i] = c;
if (c == '\n') {
line[i] = c;
++i;
}
line[i] = '\0';
return i;
}
/* copy: specialized version */
void copy(void)
{
int i;
extern char line[], longest[];
i = 0;
while ((longest[i] = line[i]) != '\0')
++i;
}
/*
Discuss:
- local vs. global/external variables
- local = automatic (created & disappear as function called/exited)
- external variables: defined exactly once outside of any functions,
declared in functions that want to use
- splitting into files, header files
*/
|
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| 15_longline.c | Download |
