#include <stdio.h>
#include <stdlib.h>
#include <time.h>
FILE *fp;
int x, y, z;
uint8_t v[1024][1024][314];
clock_t start, end;
double cpu_time_used;
uint64_t splitBy3(unsigned int a){
uint64_t x = a & 0x1fffff;
x = (x | x << 32) & 0x1f00000000ffff;
x = (x | x << 16) & 0x1f0000ff0000ff;
x = (x | x << 8) & 0x100f00f00f00f00f;
x = (x | x << 4) & 0x10c30c30c30c30c3;
x = (x | x << 2) & 0x1249249249249249;
return x;
}
uint64_t mortonEncode_magicbits(unsigned int x, unsigned int y, unsigned int z){
uint64_t answer = 0;
answer |= splitBy3(x) | splitBy3(y) << 1 | splitBy3(z) << 2;
return answer;
}
void swap(uint32_t *a, uint32_t *b) {
uint32_t t = *a;
*a = *b;
*b = t;
}
int partition(uint32_t array[], int low, int high) {
uint32_t pivot = array[high];
int i = (low - 1);
for (int j = low; j < high; j++) {
if (array[j] <= pivot) {
i++;
swap(&array[i], &array[j]);
}
}
swap(&array[i + 1], &array[high]);
return (i + 1);
}
void quickSort(uint32_t array[], int low, int high) {
if (low < high) {
int pi = partition(array, low, high);
quickSort(array, low, pi - 1);
quickSort(array, pi + 1, high);
}
}
int main(void) {
fp = fopen("c8.raw","rb");
if(fp == NULL){
printf("CHYBA S OTVORENIM");
return -1;
}
printf("Start: \n");
for (x = 0; x < 1024; x++) {
for(y = 0; y < 1024; y++){
for(z = 0; z < 314; z++){
fread(&v[x][y][z], 1, sizeof(uint8_t), fp);
}
}
}
int poc = 0;
//START
start = clock();
//printf("%d\n", v[30][100][300]);
//PRAHOVANIE
for (x = 0; x < 1024; x++) {
for(y = 0; y < 1024; y++){
for(z = 0; z < 314; z++){
if(v[x][y][z] <= 25) {
v[x][y][z] = 0;
}
else {
v[x][y][z] = 1;
poc++;
//printf("%d ", v[x][y][z]);
}
}
}
}
//MORTON ADRESY
uint32_t *voxels = (uint32_t*)malloc(poc * sizeof(uint32_t));
poc = 0;
for (x = 0; x < 1024; x++) {
for(y = 0; y < 1024; y++){
for(z = 0; z < 314; z++){
if(v[x][y][z] == 1) {
voxels[poc] = mortonEncode_magicbits(x,y,z);
poc++;
}
}
}
}
//SORTING ADRIES
quickSort(voxels, 0, poc - 1);
//END
end = clock();
//printf("\n%d", voxels[0]);
//printf("\n%d", voxels[1]);
//printf("\n%d", voxels[1000]);
//printf("\n%d", voxels[poc-1]);
//printf("\n%d", poc);
cpu_time_used = ((double) (end - start)) / CLOCKS_PER_SEC;
printf("\nSpotrebovany cas : %f\n\n", cpu_time_used);
free(voxels);
fclose(fp);
return 0;
} Write, Run & Share C Language code online using OneCompiler's C online compiler for free. It's one of the robust, feature-rich online compilers for C language, running the latest C version which is C18. Getting started with the OneCompiler's C editor is really simple and pretty fast. The editor shows sample boilerplate code when you choose language as 'C' and start coding!
OneCompiler's C online editor supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample C program which takes name as input and print your name with hello.
#include <stdio.h>
int main()
{
char name[50];
printf("Enter name:");
scanf("%s", name);
printf("Hello %s \n" , name );
return 0;
}
C language is one of the most popular general-purpose programming language developed by Dennis Ritchie at Bell laboratories for UNIX operating system. The initial release of C Language was in the year 1972. Most of the desktop operating systems are written in C Language.
When ever you want to perform a set of operations based on a condition if-else is used.
if(conditional-expression) {
// code
} else {
// code
}
You can also use if-else for nested Ifs and if-else-if ladder when multiple conditions are to be performed on a single variable.
Switch is an alternative to if-else-if ladder.
switch(conditional-expression) {
case value1:
// code
break; // optional
case value2:
// code
break; // optional
...
default:
// code to be executed when all the above cases are not matched;
}
For loop is used to iterate a set of statements based on a condition.
for(Initialization; Condition; Increment/decrement){
// code
}
While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
while(condition) {
// code
}
Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
do {
// code
} while (condition);
Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.
data-type array-name[size];
data-type array-name[size][size];
Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity.
Two types of functions are present in C
Library functions are the in-built functions which are declared in header files like printf(),scanf(),puts(),gets() etc.,
User defined functions are the ones which are written by the programmer based on the requirement.
return_type function_name(parameters);
function_name (parameters)
return_type function_name(parameters) {
//code
}