C4 运行 编译 调试 {{ example.title }} 帮助 输出窗口:

# Copyright 2016 ChaiShushan <chaishushan{AT}gmail.com>. All rights reserved.
# Use of this source code is governed by a BSD-style
# license that can be found in the LICENSE file.

// comments
// comments

/*
	comments
	comments * /
// */

#include <stdio.h>
#include <hello, world.h>

/* */int main()
{
  printf("hello, world\n");
  printf("#include <hello, world.h>\n");
  return 0;
}
/*

// Copyright 2016 ChaiShushan <chaishushan{AT}gmail.com>. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#include <stdio.h>

int main() {
	int i, sum;

	i = 0;
	sum = 0;

	while(i <= 100) {
		sum = sum+i;
		i++;
	}

	printf("sum(1+..+100) = %d\n", sum);
	return 0;
}

// Copyright 2016 ChaiShushan <chaishushan{AT}gmail.com>. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#include <stdio.h>

int main() {
	int t1, t2, next;

	t1 = t2 = 1;
	printf("%d %d ", t1, t2);

	next = t1 + t2;
	while(next <= 1000) {
		printf("%d ",next);
		t1 = t2; t2 = next;
		next = t1 + t2;
	}
	printf("\n");
	return 0;
}

// Copyright 2016 ChaiShushan <chaishushan{AT}gmail.com>. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#include <stdio.h>

int is_prime(int n) {
	int i;
	i = 2;
	while(i*i <= n) {
		if(n%i == 0) return 0;
		i++;
	}
	return 1;
}

int main() {
	int i;
	i = 2;
	while(i < 20) {
		if(is_prime(i)) {
			printf("%d\n", i);
		}
		i++;
	}
	return 0;
}

// Copyright 2016 ChaiShushan <chaishushan{AT}gmail.com>. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

int gcd(int m, int n) {
	return n? gcd(n, m%n): m;
}

int main() {
	printf("gcd(27,15): %d\n", gcd(27,15));
	return 0;
}

// Copyright 2016 ChaiShushan <chaishushan{AT}gmail.com>. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#include <stdio.h>
#include <stdlib.h>

int gcd(int m, int n) {
	return n? gcd(n, m%n): m;
}

int gcd_stk(int m, int n) {
	int *stk;
	int sp;
	int ret;

	stk = malloc(1024);
	sp = 0;

	// push call frame
	stk[sp+0] = 0; // return value
	stk[sp+1] = 0; // return flag
	stk[sp+2] = m; // push m
	stk[sp+3] = n; // push n
	sp = sp + 4;

	while(sp > 0) {
		m = stk[sp-2];
		n = stk[sp-1];

		if(stk[sp-3]) {
			stk[sp-4] = stk[sp]; // return gcd(n, m%n);
			sp = sp - 4;         // pop call frame
		} else if(n == 0) {
			stk[sp-4] = m;   // if(n == 0) return m;
			sp = sp - 4;     // pop call frame
		} else {
			stk[sp-3] = 1;   // parent call is in return path

			// push call frame
			stk[sp+0] = 0;   // return value
			stk[sp+1] = 0;   // return flag
			stk[sp+2] = n;   // push n
			stk[sp+3] = m%n; // push m%n
			sp = sp + 4;
		}
	}

	ret = stk[sp];
	free(stk);
	return ret;
}

int main() {
	printf("gcd(27,15): %d\n", gcd(27,15));
	printf("gcd(12,18): %d\n", gcd(12,18));
	printf("gcd(13,19): %d\n", gcd(13,19));

	printf("gcd_stk(27,15): %d\n", gcd_stk(27,15));
	printf("gcd_stk(12,18): %d\n", gcd_stk(12,18));
	printf("gcd_stk(13,19): %d\n", gcd_stk(13,19));

	return 0;
}

// Copyright 2016 ChaiShushan <chaishushan{AT}gmail.com>. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#include <stdio.h>
#include <stdlib.h>

int main() {
	char *name;
	int fd;
	char *p;
	int i;

	// embedded file
	name = "data/hello.c";

	// open for readonly
	fd = open(name, 0);
	if(fd < 0) {
		printf("could not open(%s) file\n", name);
		return -1;
	}

	p = malloc(1024);
	i = read(fd, p, 1024-1);
	close(fd);

	if(i <= 0) {
		free(p);
		printf("read() returned %d\n", i); return -1;
		return -1;
	}
	p[i] = 0;

	printf("%s", p);
	free(p);
	return 0;
}

main(a){printf(a="main(a){printf(a=%c%s%c,34,a,34);}",34,a,34);}