C: sum of multiples + complex numbers

This commit is contained in:
2021-08-15 16:58:11 +02:00
parent ccb96a4f2a
commit e357f5c26a
12 changed files with 546 additions and 5 deletions

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@@ -0,0 +1,51 @@
# The original 'makefile' has a flaw:
# 1) it overrides CFLAGS
# 2) it does not pass extra "FLAGS" to $(CC) that could come from environment
#
# It means :
# - we need to edit 'makefile' for different builds (DEBUG, etc...), which is
# not practical at all.
# - Also, it does not allow to run all tests without editing the test source
# code.
#
# To use this makefile (GNU make only):
# "make": build with all predefined tests (without editing test source code)
# "make debugall": build with all predefined tests and debug code
# "make mem": perform memcheck with all tests enabled
# "make unit": build standalone (unit) test
# "make debug": build standalone test with debugging code
#
# Original 'makefile' targets can be used (test, memcheck, clean, ...)
.PHONY: default all mem unit debug std debugtest
default: all
# default is to build with all predefined tests
BUILD := teststall
include makefile
all: CFLAGS+=-DTESTALL
all: clean test
debugall: CFLAGS+=-DDEBUG
debugall: all
debugtest: CFLAGS+=-DDEBUG
debugtest: test
mem: CFLAGS+=-DTESTALL
mem: clean memcheck
unit: CFLAGS+=-DUNIT_TEST
unit: clean std
debug: CFLAGS+=-DUNIT_TEST -DDEBUG
debug: clean std
debugtest: CFLAGS+=-DDEBUG
debugtest: test
std: src/*.c src/*.h
$(CC) $(CFLAGS) src/*.c -o test.out

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@@ -0,0 +1,67 @@
# Complex Numbers
A complex number is a number in the form `a + b * i` where `a` and `b` are real and `i` satisfies `i^2 = -1`.
`a` is called the real part and `b` is called the imaginary part of `z`.
The conjugate of the number `a + b * i` is the number `a - b * i`.
The absolute value of a complex number `z = a + b * i` is a real number `|z| = sqrt(a^2 + b^2)`. The square of the absolute value `|z|^2` is the result of multiplication of `z` by its complex conjugate.
The sum/difference of two complex numbers involves adding/subtracting their real and imaginary parts separately:
`(a + i * b) + (c + i * d) = (a + c) + (b + d) * i`,
`(a + i * b) - (c + i * d) = (a - c) + (b - d) * i`.
Multiplication result is by definition
`(a + i * b) * (c + i * d) = (a * c - b * d) + (b * c + a * d) * i`.
The reciprocal of a non-zero complex number is
`1 / (a + i * b) = a/(a^2 + b^2) - b/(a^2 + b^2) * i`.
Dividing a complex number `a + i * b` by another `c + i * d` gives:
`(a + i * b) / (c + i * d) = (a * c + b * d)/(c^2 + d^2) + (b * c - a * d)/(c^2 + d^2) * i`.
Raising e to a complex exponent can be expressed as `e^(a + i * b) = e^a * e^(i * b)`, the last term of which is given by Euler's formula `e^(i * b) = cos(b) + i * sin(b)`.
Implement the following operations:
- addition, subtraction, multiplication and division of two complex numbers,
- conjugate, absolute value, exponent of a given complex number.
Assume the programming language you are using does not have an implementation of complex numbers.
## Getting Started
Make sure you have read the "Guides" section of the
[C track][c-track] on the Exercism site. This covers
the basic information on setting up the development environment expected
by the exercises.
## Passing the Tests
Get the first test compiling, linking and passing by following the [three
rules of test-driven development][3-tdd-rules].
The included makefile can be used to create and run the tests using the `test`
task.
make test
Create just the functions you need to satisfy any compiler errors and get the
test to fail. Then write just enough code to get the test to pass. Once you've
done that, move onto the next test.
As you progress through the tests, take the time to refactor your
implementation for readability and expressiveness and then go on to the next
test.
Try to use standard C99 facilities in preference to writing your own
low-level algorithms or facilities by hand.
## Source
Wikipedia [https://en.wikipedia.org/wiki/Complex_number](https://en.wikipedia.org/wiki/Complex_number)
## Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
[c-track]: https://exercism.io/my/tracks/c
[3-tdd-rules]: http://butunclebob.com/ArticleS.UncleBob.TheThreeRulesOfTdd

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@@ -0,0 +1,38 @@
### If you wish to use extra libraries (math.h for instance),
### add their flags here (-lm in our case) in the "LIBS" variable.
LIBS = -lm
###
CFLAGS = -std=c99
CFLAGS += -g
CFLAGS += -Wall
CFLAGS += -Wextra
CFLAGS += -pedantic
CFLAGS += -Werror
CFLAGS += -Wmissing-declarations
CFLAGS += -DUNITY_SUPPORT_64
CFLAGS += -DUNITY_INCLUDE_DOUBLE
ASANFLAGS = -fsanitize=address
ASANFLAGS += -fno-common
ASANFLAGS += -fno-omit-frame-pointer
.PHONY: test
test: tests.out
@./tests.out
.PHONY: memcheck
memcheck: test/*.c src/*.c src/*.h
@echo Compiling $@
@$(CC) $(ASANFLAGS) $(CFLAGS) src/*.c test/vendor/unity.c test/*.c -o memcheck.out $(LIBS)
@./memcheck.out
@echo "Memory check passed"
.PHONY: clean
clean:
rm -rf *.o *.out *.out.dSYM
tests.out: test/*.c src/*.c src/*.h
@echo Compiling $@
@$(CC) $(CFLAGS) src/*.c test/vendor/unity.c test/*.c -o tests.out $(LIBS)

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#include "complex_numbers.h"
#ifdef USE_COMPLEX_FUNCTIONS
complex_t c_add(complex_t a, complex_t b)
{
return (complex_t) {
.real = a.real+b.real,
.imag = a.imag+b.imag
};
}
complex_t c_sub(complex_t a, complex_t b)
{
return (complex_t) {
.real = a.real-b.real,
.imag = a.imag-b.imag
};
}
complex_t c_mul(complex_t a, complex_t b)
{
return (complex_t) {
.real = a.real*b.real - a.imag*b.imag,
.imag = a.imag*b.real + a.real*b.imag,
};
}
complex_t c_div(complex_t a, complex_t b)
{
double d = b.real*b.real + b.imag*b.imag;
return (complex_t) {
.real = (a.real*b.real + a.imag*b.imag)/d,
.imag = (a.imag*b.real - a.real*b.imag)/d
};
}
double c_abs(complex_t x)
{
return sqrt(x.real*x.real + x.imag*x.imag);
}
complex_t c_conjugate(complex_t x)
{
return (complex_t) {
.real = x.real,
.imag = -x.imag
};
}
double c_real(complex_t x)
{
return x.real;
}
double c_imag(complex_t x)
{
return x.imag;
}
complex_t c_exp(complex_t x)
{
return (complex_t) {
.real = exp(x.real)*cos(x.imag),
.imag = exp(x.real)*sin(x.imag)
};
}
#endif
/* See GNUmakefile below for explanation
* https://github.com/braoult/exercism/blob/master/c/templates/GNUmakefile
*/
#ifdef UNIT_TEST
#include <stdio.h>
#include <stdlib.h>
int main(int ac, char **av)
{
int arg=1;
complex_t c1, c2, c3;
for (; arg<ac-3; ++arg, ++arg) {
c1.real=atof(av[arg]);
c1.imag=atof(av[arg+1]);
c2.real=atof(av[arg+2]);
c2.imag=atof(av[arg+3]);
c3 = c_add(c1, c2);
printf("(%f + %fi) + (%f + %fi) = (%f + %fi)\n",
c1.real, c1.imag,
c2.real, c2.imag,
c3.real, c3.imag);
}
}
#endif

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#ifndef _COMPLEX_NUMBERS_H_
#define _COMPLEX_NUMBERS_H_
#include <math.h>
typedef struct {
double real;
double imag;
} complex_t;
/* default is to use macros */
#ifdef USE_COMPLEX_FUNCTIONS
complex_t c_add(complex_t a, complex_t b);
complex_t c_sub(complex_t a, complex_t b);
complex_t c_mul(complex_t a, complex_t b);
complex_t c_div(complex_t a, complex_t b);
double c_abs(complex_t x);
complex_t c_conjugate(complex_t x);
double c_real(complex_t x);
double c_imag(complex_t x);
complex_t c_exp(complex_t x);
#else
#define c_add(a,b) (complex_t) { \
(a).real+(b).real, \
(a).imag+(b).imag }
#define c_sub(a,b) (complex_t) { \
(a).real-(b).real, \
(a).imag-(b).imag }
#define c_mul(a,b) (complex_t) { \
(a).real*(b).real - (a).imag*(b).imag, \
(a).imag*(b).real + (a).real*(b).imag }
#define c_div(a,b) (complex_t) { \
((a).real*(b).real + (a).imag*(b).imag)/ \
((b).real*(b).real + (b).imag*(b).imag), \
((a).imag*(b).real - (a).real*(b).imag)/ \
((b).real*(b).real + (b).imag*(b).imag) }
#define c_exp(x) (complex_t) { \
exp((x).real) * cos((x).imag), \
exp((x).real) * sin((x).imag) }
#define c_abs(x) { sqrt((x).real*(x).real + (x).imag*(x).imag) }
#define c_conjugate(x) (complex_t){ (x).real, -(x).imag }
#define c_real(x) (x).real
#define c_imag(x) (x).imag
#endif
/* See GNUmakefile below for explanation
* https://github.com/braoult/exercism/blob/master/c/templates/GNUmakefile
*/
#if defined UNIT_TEST || defined DEBUG
#include <stdio.h>
#include <stdlib.h>
#endif
#ifdef TESTALL
#undef TEST_IGNORE
#define TEST_IGNORE() {}
#endif
#endif

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@@ -39,7 +39,7 @@ int add_student(char *s, uint8_t g)
*/
roster_t get_grade(uint8_t g)
{
static roster_t r;
roster_t r;
unsigned i, j=0;
for (i=0; i<roster.count && GRADE(i)<=g; ++i) {

14
c/square-root/src/square_root.c Normal file → Executable file
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@@ -28,10 +28,9 @@ unsigned square_root(unsigned i)
if (i<=1) /* 0 and 1 */
return i;
//nbits = (sizeof(unsigned) * 8);
for (j = 4, max = 16L;; j += 2, max <<= 2L) {
for (j = 4, max = 16;; j += 2, max <<= 2) {
if (j >= NBITS || i <= max) {
sq2 = (1L << (j >> 1));
sq2 = (1 << (j >> 1));
break;
}
}
@@ -45,11 +44,18 @@ unsigned square_root(unsigned i)
#ifdef UNIT_TEST
int main(int ac, char **av)
{
unsigned i, j;
unsigned i;
/* int arg=1;
for (; arg<ac; ++arg) {
i=atol(av[arg]);
printf("sqrt(%u)=%u\n", i, square_root(i));
}
*/
if (ac && *av)
for (i=0; i<100000000; ++i)
square_root(65025);
printf("sq=%u\n", square_root(65536));
}
#endif

51
c/sum-of-multiples/GNUmakefile Executable file
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# The original 'makefile' has a flaw:
# 1) it overrides CFLAGS
# 2) it does not pass extra "FLAGS" to $(CC) that could come from environment
#
# It means :
# - we need to edit 'makefile' for different builds (DEBUG, etc...), which is
# not practical at all.
# - Also, it does not allow to run all tests without editing the test source
# code.
#
# To use this makefile (GNU make only):
# "make": build with all predefined tests (without editing test source code)
# "make debugall": build with all predefined tests and debug code
# "make mem": perform memcheck with all tests enabled
# "make unit": build standalone (unit) test
# "make debug": build standalone test with debugging code
#
# Original 'makefile' targets can be used (test, memcheck, clean, ...)
.PHONY: default all mem unit debug std debugtest
default: all
# default is to build with all predefined tests
BUILD := teststall
include makefile
all: CFLAGS+=-DTESTALL
all: clean test
debugall: CFLAGS+=-DDEBUG
debugall: all
debugtest: CFLAGS+=-DDEBUG
debugtest: test
mem: CFLAGS+=-DTESTALL
mem: clean memcheck
unit: CFLAGS+=-DUNIT_TEST
unit: clean std
debug: CFLAGS+=-DUNIT_TEST -DDEBUG
debug: clean std
debugtest: CFLAGS+=-DDEBUG
debugtest: test
std: src/*.c src/*.h
$(CC) $(CFLAGS) src/*.c -o test.out

47
c/sum-of-multiples/README.md Executable file
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@@ -0,0 +1,47 @@
# Sum Of Multiples
Given a number, find the sum of all the unique multiples of particular numbers up to
but not including that number.
If we list all the natural numbers below 20 that are multiples of 3 or 5,
we get 3, 5, 6, 9, 10, 12, 15, and 18.
The sum of these multiples is 78.
## Getting Started
Make sure you have read the "Guides" section of the
[C track][c-track] on the Exercism site. This covers
the basic information on setting up the development environment expected
by the exercises.
## Passing the Tests
Get the first test compiling, linking and passing by following the [three
rules of test-driven development][3-tdd-rules].
The included makefile can be used to create and run the tests using the `test`
task.
make test
Create just the functions you need to satisfy any compiler errors and get the
test to fail. Then write just enough code to get the test to pass. Once you've
done that, move onto the next test.
As you progress through the tests, take the time to refactor your
implementation for readability and expressiveness and then go on to the next
test.
Try to use standard C99 facilities in preference to writing your own
low-level algorithms or facilities by hand.
## Source
A variation on Problem 1 at Project Euler [http://projecteuler.net/problem=1](http://projecteuler.net/problem=1)
## Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
[c-track]: https://exercism.io/my/tracks/c
[3-tdd-rules]: http://butunclebob.com/ArticleS.UncleBob.TheThreeRulesOfTdd

37
c/sum-of-multiples/makefile Executable file
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@@ -0,0 +1,37 @@
### If you wish to use extra libraries (math.h for instance),
### add their flags here (-lm in our case) in the "LIBS" variable.
LIBS = -lm
###
CFLAGS = -std=c99
CFLAGS += -g
CFLAGS += -Wall
CFLAGS += -Wextra
CFLAGS += -pedantic
CFLAGS += -Werror
CFLAGS += -Wmissing-declarations
CFLAGS += -DUNITY_SUPPORT_64
ASANFLAGS = -fsanitize=address
ASANFLAGS += -fno-common
ASANFLAGS += -fno-omit-frame-pointer
.PHONY: test
test: tests.out
@./tests.out
.PHONY: memcheck
memcheck: test/*.c src/*.c src/*.h
@echo Compiling $@
@$(CC) $(ASANFLAGS) $(CFLAGS) src/*.c test/vendor/unity.c test/*.c -o memcheck.out $(LIBS)
@./memcheck.out
@echo "Memory check passed"
.PHONY: clean
clean:
rm -rf *.o *.out *.out.dSYM
tests.out: test/*.c src/*.c src/*.h
@echo Compiling $@
@$(CC) $(CFLAGS) src/*.c test/vendor/unity.c test/*.c -o tests.out $(LIBS)

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@@ -0,0 +1,57 @@
#include <stdio.h>
#include <malloc.h>
/* V1: initial version
* V2: bug fix: force full unsigned allocation instead of bytes.
*/
#include "sum_of_multiples.h"
#define BITS (sizeof(unsigned)*8)
#define getbit(i) (!!(sieve[(i) / BITS] & (1 << ((i) % BITS))))
#define setbit(i) (sieve[(i) / BITS] |= (1 << ((i) % BITS)))
/* use a kind of eratosthenes's sieve, to avoid the trivial solution :-)
*/
unsigned sum(const unsigned *f, const size_t n, const unsigned l)
{
unsigned sieve_size = (l-1)/BITS+1;
unsigned num, i, res=0;
unsigned *sieve;
sieve = calloc(sieve_size, sizeof(unsigned)); /* l bits array */
if (!sieve)
return 0;
for (i=0; i<n; ++i) {
if (f[i]) {
for (num=f[i]; num<l; num+=f[i]) {
if (!getbit(num)) {
res+=num;
setbit(num);
}
}
}
}
free(sieve);
return res;
}
/* See GNUmakefile below for explanation
* https://github.com/braoult/exercism/blob/master/c/templates/GNUmakefile
*/
#ifdef UNIT_TEST
int main(int ac, char **av)
{
unsigned input[256];
int last, i;
if (ac>2) {
last=atol(av[1]);
for (i=2; i<ac; ++i) {
input[i-2]=atoi(av[i]);
}
printf("sum(..., %u, %u)=%u\n", i-2, last,
sum(input, (unsigned)i-2, (unsigned)last));
}
}
#endif

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@@ -0,0 +1,21 @@
#ifndef SUM_OF_MULTIPLES_H
#define SUM_OF_MULTIPLES_H
#include <stddef.h>
unsigned int sum(const unsigned int *factors,
const size_t number_of_factors, const unsigned int limit);
/* See GNUmakefile below for explanation
* https://github.com/braoult/exercism/blob/master/c/templates/GNUmakefile
*/
#if defined UNIT_TEST || defined DEBUG
#include <stdio.h>
#include <stdlib.h>
#endif
#ifdef TESTALL
#undef TEST_IGNORE
#define TEST_IGNORE() {}
#endif
#endif