Daily C language exercises-1.2

1. Output the following pattern on the screen:
*
***
*****
******
*********
***********
***** ********
************
*********
*******
*****
***
*

    int i = 0,
	    j = 0;
	for (i = 0; i <= 6; i++)
	{
		for (j = 0; j <= 2 * i; j++)
			printf("*");
		printf("\n");
	}

	for (i = 0; i <= 5; i++)
	{
		for (j = 0; j <= 10 - 2 * i; j++)
			printf("*");
		printf("\n");
	}

2. Find all "daffodils" between 0 and 999 and output.

"Daffodil number" refers to a three-digit number whose cubic sum of each number is exactly equal to the number itself, such as; 153=1^3+5^3+3^3,

  Then 153 is a "daffodil number".

#include <stdio.h>
#include <Windows.h>
#include <math.h>
int main() {
	for (int i = 100; i <= 999; i++) {
		//Intercept the ones and tens, hundreds
		int a = i % 10;
		int b = i / 10 % 10;
		int c = i / 100 % 10;

		if (pow(a, 3) + pow(b, 3) + pow(c, 3) == a * 100 + b * 10 + c) {
			printf("%d%d%d \n", a, b, c);
		}	

	}

	system("pause");
	return 0;

}

3. Find the sum of the first 5 terms of Sn = a + aa + aaa + aaaa + aaaaa, where a is a number, for example: 2 + 22 + 222 + 2222 + 22222

    int a,
		n,
		t = 0,
		Sn = 0;
	printf("Enter a and n:\n");
	scanf_s("%d%d", &a, &n);
	for (int i = 1; i <= n; i++)
	{
		t = t * 10 + a;
		Sn += t;
	}
	printf("Sn=%d\n", Sn);

4. Write a program that reads C source code from standard input and verifies that all curly braces are paired correctly.

    int a,
		account = 0;
	printf("Please enter the code:\n");
	while ((a = getchar()) != EOF)
	{
		if (a == '{')
		{
			account++;
		}
		else if (a == '}' && account == 0)
		{
			printf("The curly braces are not paired\n");
			return 0;
		}
		else if (a == '}' && account != 0)
		{
			account--;
		}
	}

	if (account > 0)
	{
		printf("The curly braces are not paired\n");
	}
	else
	{
		printf("Paired curly braces\n");
	}