C/C++ 在线编译器

C Playground：选择 C11 或 C++17，在浏览器里用 clang 编译运行，无需安装编译器，也无需上传源码。适合验证小程序、练习算法和查看编译诊断。

使用 scanf / cin 时，请先填好 stdin；运行期间不能追加输入。单次执行限时 5 秒，C++ 不支持异常。首次打开需要下载 WebAssembly 工具链。

使用指南：编译原理与限制 · scanf 与 stdin · 读懂 clang 报错

// playground.cc

> vim main.cpp

Write C/C++ freely in the left editor, then click run to compile and execute. Examples are for reference only; stdin is only needed when your program reads input.

file: main.cppexampletoolchain: loading

loading toolchain0%

main.cppMonaco · CPP

stdin (for cin / scanf)

output · idle

Run your code to see output here.

// man playground

- The main editor accepts any C/C++ code; drafts are saved locally in your browser.
- The example dropdown loads code only and preserves stdin. Use 载入示例输入 beside stdin to try its sample input.
- stdin is only required when your program reads input; leave it empty for hello world.
- Shortcut: Cmd/Ctrl + Enter to run; execution stops automatically after 5 seconds.
- Compile errors show structured diagnostics; click to jump to the line.
- Share copies a gzip-compressed link (?lang=cpp&z=...) that restores code and stdin.

// playground.cc

> make toolchain

// loading playground...

// quick start

从一个能运行的例子开始 · Run your first program

打开示例会同时载入代码和输入；等待 toolchain ready 后点击 run，再对照预期输出。示例是只读的，不会覆盖你的代码草稿或 stdin。用浏览器返回后默认打开 C++；选择 C 可继续之前的 C 草稿。

Open an example, wait for toolchain ready, then click run and compare stdout below. Read-only examples keep your saved code and input intact. Go Back to the C++ editor; select C again to resume your C draft.

C · Hello World

用 printf 输出一行文字，不需要输入。Print a line with printf; no input needed.

stdin · 输入: 无需输入 · empty
stdout · 预期输出: Hello, World

查看代码 · View hello.c

#include <stdio.h>

int main(void) {
    printf("Hello, World\n");
    return 0;
}

运行 hello.c · read-only

C · scanf 输入求和

用 scanf 读取两个整数，再输出它们的和。Read two integers from stdin and print their sum.

stdin · 输入: 3 4
stdout · 预期输出: 7

查看代码 · View a+b.c

#include <stdio.h>

int main(void) {
    int a, b;
  if (scanf("%d %d", &a, &b) != 2) {
    return 1;
  }
    printf("%d\n", a + b);
    return 0;
}

运行 a+b.c · read-only

C++ · std::sort 排序

先输入个数，再输入整数序列，按升序输出。Read a count and its integers, then sort them in ascending order.

stdin · 输入: 5 4 1 5 2 3
stdout · 预期输出: 1 2 3 4 5

查看代码 · View sort.cpp

#include <algorithm>
#include <iostream>
#include <sstream>
#include <string>
#include <vector>

bool read_int(int& value) {
    std::string token;
    if (!(std::cin >> token)) {
        return false;
    }
    std::istringstream parser(token);
    return (parser >> value) && parser.eof();
}

int main() {
    int n;
    if (!read_int(n) || n < 0 || n > 10000) {
        std::cerr << "Expected a count from 0 to 10000.\n";
        return 1;
    }
    std::vector<int> values(n);
    for (int& value : values) {
        if (!read_int(value)) {
            std::cerr << "Expected " << n << " integers after the count.\n";
            return 1;
        }
    }
    std::sort(values.begin(), values.end());
    for (int value : values) {
        std::cout << value << " ";
    }
    std::cout << "\n";
    return 0;
}

运行 sort.cpp · read-only

想修改例子？在上方编辑器选择 C 或 C++，再从 example 菜单载入同名代码。菜单只替换代码；需要输入时，点击 stdin 旁的「载入示例输入」。 To edit, choose the matching language and example in the editor above, then load its sample input beside stdin.