C language: print rhombus

Topic: Printing a Rhombus

Background: None.

Idea: Use two for loops, use mathematical knowledge, and deduce the law

code:

#include<stdio.h>

int main()
{
	int i, j;
	//上半部分
	for (i = 0; i < 4; i++)
	{
		//打印空格
		for (j = 0; j < 3 - i; j++)
		{
			printf(" ");
		}
		//打印 * 
		for (j = 0; j < 2 * i + 1; j++)
		{
			printf("*");
		}
		printf("\n");
	}
	//下半部分
	for (i = 0; i < 3; i++)
	{
		//打印空格
		for (j = 0; j < i + 1; j++)
		{
			printf(" ");
		}
		//打印 *
		for (j = 0; j < 5 - 2 * i; j++)
		{
			printf("*");
		}
		printf("\n");
	}
	return 0;
}

Details: Note every derivation formula.