# Printing of common patterns using loop in C

Aug. 14, 2017 12899 Printing of patterns using loops is a common question asked to a beginner and is a good practice to make strong grip over loops. This post contains the codes of various patterns. Read the comments in the code to understand the logic.

*
**
***
****
*****

*****
****
***
**
*

*
***
*****
*******
*********

*   *
* *
*
* *
*   *

*****
*
*
*
*****

*****
*
*
*
*****

*****
*    *
*    *
*    *
*****

*****
*****
*****
*****
*****

*****
*****
*****
*****
*****

1
12
123
1234
12345
1234
123
12
1

//Right angled traingle upward
#include <stdio.h>
int main()
{
int height, i, j, k;
printf("Enter height\n");
scanf("%d",&height);

//number of lines is equal to height
for(i=1; i<=height; i++)
{
//number of stars in each line is
//equal to the line number
for(j=1; j<=i; j++)
{
printf("*");
}
//new line after each line
printf("\n");
}
return 0;
}

//Right angled triangle downward
#include <stdio.h>
int main()
{
int height, i, j, k;
printf("Enter height\n");
scanf("%d",&height);
for(i=height; i>=1; i--)
{
//number of stars in each line is
//equal to i
for(j=1; j<=i; j++)
{
printf("*");
}
//new line after each line
printf("\n");
}
return 0;
}

//Triangle
#include <stdio.h>
int main()
{
int height, i, j, k;
printf("Enter height\n");
scanf("%d",&height);
//Number of lines is equal to height
for(i=1; i<=height; i++)
{
//Number of spaces in each line is
//equal to height – line number
for(j=1; j<=height-i;j++)
{
printf(" ");
}
//number of stars in each line is equal to
//(2*line number) – 1
for(j=1; j<=(2*i)-1; j++)
{
printf("*");
}
printf("\n");
}
return 0;
}

//cross
#include <stdio.h>
int main()
{
int height, i, j, k;
printf("Enter height\n");
scanf("%d",&height);
for(i=1; i<=height; i++)
{
for(j=1; j<=height; j++)
{
//in a cross,
//star will be printed if
//i is j – digonal line
//or height-j+1 – another digonal line
if(i==j || height-j+1==i)
printf("*");
else
printf(" ");
}
printf("\n");
}
return 0;
}

//z
#include <stdio.h>
int main()
{
int height, i, j, k;
printf("Enter height\n");
scanf("%d",&height);
for(i=1; i<=height; i++)
{
for(j=height; j>=1; j--)
{
//i=j – to print one digonal line
//i==1 – First line will contain only stars
//i == height – Last line will be of stars only
if(i==1 || i==height || i==j)
printf("*");
else
printf(" ");
}
printf("\n");
}
return 0;
}

//reverse z
#include <stdio.h>
int main()
{
int height, i, j, k;
printf("Enter height\n");
scanf("%d",&height);
for(i=1; i<=height; i++)
{
for(j=1; j<=height; j++)
{
if(i==1 || i==height || i==j)
printf("*");
else
printf(" ");
}
printf("\n");
}
return 0;
}

//hollow square
#include <stdio.h>
int main()
{
int height, i, j, k;
printf("Enter height\n");
scanf("%d",&height);
for(i=1; i<=height; i++)
{
for(j=1; j<=height; j++)
{
//stars will be printed at top, bottom and side edges
//j==1 for left side edge
//j==height for right side edge
//i==1 for top line
//i==height for last line
if(j==1 || j==height || i==1 || i==height)
printf("*");
else
printf(" ");
}
printf("\n");
}
return 0;
}

//solid square
#include <stdio.h>
int main()
{
int height, i, j, k;
printf("Enter height\n");
scanf("%d",&height);
for(i=1; i<=height; i++)
{
for(j=1; j<=height; j++)
{
printf("*");
}
printf("\n");
}
return 0;
}

//rhombus
#include <stdio.h>
int main()
{
int height, i, j, k;
printf("Enter height\n");
scanf("%d",&height);
for(i=1; i<=height; i++)
{
for(k=1; k<=i-1;k++)
{
printf(" ");
}

for(j=1; j<=height; j++)
{
printf("*");
}
printf("\n");
}
return 0;
}

#include <stdio.h>
int main()
{
int height, i, j, k;
printf("Enter height\n");
scanf("%d",&height);
for(i=1; i<=height; i++)
{
for(j=1; j<=i; j++)
{
printf("%d",j);
}
printf("\n");
}
for(i=height-1; i>=1; i--)
{
for(j=1; j<=i; j++)
{
printf("%d",j);
}
printf("\n");
}
return 0;
}


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