小编Jay*_*jee的帖子

我正在试验各种编程语言中双精度值的精度。

我的节目

主文件

#include <stdio.h>

int main() {
    for (double i = 0.0; i < 3; i = i + 0.1) {
        printf("%.17lf\n", i);
    }
    return 0;
}

主程序

#include <iostream>

using namespace std;

int main() {
    cout.precision(17);
    for (double i = 0.0; i < 3; i = i + 0.1) {
        cout << fixed << i << endl;
    }
    return 0;
}

主文件

i = 0.0
while i < 3:
    print(i)
    i = i + 0.1

主程序

public class …

我在 VScode 上使用了调试工具（ctrl + shift + D）和自定义的 launch.json，但我无法运行我的程序。帮我解决这个问题。 这是我的回溯

Traceback (most recent call last):
File "/usr/lib/python3.6/runpy.py", line 193, in _run_module_as_main
 "__main__", mod_spec)
File "/usr/lib/python3.6/runpy.py", line 85, in _run_code
 exec(code, run_globals)
File "/home/odroid/.vscode-server/extensions/ms-python.python-2020.12.424452561/pythonFiles/lib/python/debugpy/__main__.py", line 45, in <module>
 cli.main()
File "/home/odroid/.vscode-server/extensions/ms-python.python-2020.12.424452561/pythonFiles/lib/python/debugpy/../debugpy/server/cli.py", line 444, in main
 run()
File "/home/odroid/.vscode-server/extensions/ms-python.python-2020.12.424452561/pythonFiles/lib/python/debugpy/../debugpy/server/cli.py", line 285, in run_file
 runpy.run_path(target_as_str, run_name=compat.force_str("__main__"))
File "/usr/lib/python3.6/runpy.py", line 261, in run_path
 code, fname = _get_code_from_file(run_name, path_name)
File "/usr/lib/python3.6/runpy.py", line 236, in _get_code_from_file
 code = compile(f.read(), fname, 'exec')
File "/home/odroid/Documents/python/crawling-worker/.vscode/launch.json", line 2
 // Use …

我正在尝试使用光线行进渲染球体网格。SDF 函数如下所示：

float sq_layer(vec3 p, vec3 bounding_box_min, vec3 bounding_box_max)
{
         float cell_size = 4.0 / 16.0;
         vec3 p0 = clamp(p.xyz, bounding_box_min, bounding_box_max);
         p0 = mod(p0, cell_size) - cell_size * 0.5f;
         float d_pt = sphereSDF(vec3(p0.x, p0.y, p0.z), 0.05f)
         return d_pt;
}

但我得到这样的东西：

为了获得更多相关性，我尝试稍微更改一下代码：

float sq_layer(vec3 p, vec3 bounding_box_min, vec3 bounding_box_max)
{
         vec3 cell_size = (bounding_box_max - bounding_box_min)  / 4.0;
         vec3 p0 = clamp(p.xyz, bounding_box_min, bounding_box_max);
         p0 = mod(p0, cell_size) - cell_size * 0.5f;
         float d_pt = boxSDF(p0, cell_size * 0.35);
         return …

我在下面的代码中的最后一个 elif 和 else 语句有一个相当简单的问题......它们根本不会执行。我是 python 的大菜鸟，所以很可能是一个简单的错误：/控制台不显示任何语法错误或任何东西......它执行代码，但结果错误

            starthandvalue = 0

            if splitfirstcard[0] == splitsecondcard[0]:
                ispar = True
                
                if (splitfirstcard[0] and splitsecondcard[0] == 'A') or (splitfirstcard[0] and splitsecondcard[0]== 'K') or (splitfirstcard[0] and splitsecondcard[0] == 'Q'):
                    starthandvalue =+83
                    
                elif (splitfirstcard[0] and splitsecondcard[0] == 'J') or (splitfirstcard[0] and splitsecondcard[0] == '10') or (splitfirstcard[0] and splitsecondcard[0] == '9'):
                    starthandvalue =+75

                elif (splitfirstcard[0] and splitsecondcard[0] == '8') or (splitfirstcard[0] and splitsecondcard[0] == '7') or (splitfirstcard[0] and splitsecondcard[0] == '6') or (splitfirstcard[0] and splitsecondcard[0] == '5'): …

所以，我对 C 完全陌生。我正在测试这些语言的性能。

我做了什么？

我用 C 编写了两个程序，一个是用 Java 编写的，它们都做同样的事情，但是与 Java 相比，C 非常慢？

以下是程序：

主文件：

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

void work();

int main() {
    time_t seconds;     
    seconds = time(NULL); 
    printf("time1 : %ld\n", seconds);
    work();
    seconds = time(NULL); 
    printf("time2 : %ld\n", seconds);
    return 0;
}

void work() {
    int a[1000][500];
    for (int k = 0; k < 10000; ++k) {
        for (int i = 0; i < 1000; ++i) {
            for (int j = 0; j < 500; ++j) …