C Program for Arrow Star Pattern

Given a number n and we have to print the arrow star pattern of maximum n number of stars.

The star pattern of input 4 will look like −

Example

Input: 3
Output:

Input: 5
Output:

The approach used below is as follows −

• Take input in integer.
• Then print n spaces and n stars.
• Decrement till n>1.
• Now increment till n.
• And print spaces and stars in increasing order.

Algorithm

Start
In function int arrow(int num)
   Step 1-> declare and initialize i, j
   Step 2-> Loop For i = 1 and i <= num and i++
      Loop For j = i and j < num and j++
         Print a space
      Loop For j = i and j <= num and j++
         Print "*"
         Print newline
   Step 3-> Loop For i = 2 and i <= num and i++
      Loop For j= 1 and j < I and j++
         Print a space
      Loop For j = 1 and j <= i and j++
         Print "*"
         Print newline
In function int main()
   Step 1-> declare and initialize num = 4
   Step 2-> call arrow(num)

Example

 Live Demo

#include <stdio.h>
// arrow function
int arrow(int num) {
   int i, j;
   // Prints the upper part of the arrow
   for (i = 1; i <= num; i++) {
      // to print the spaces
      for (j = i; j < num; j++) {
         printf(" ");
      }
      // to print the * for the pattern
      for (j = i; j <= num; j++) {
         printf("*");
      }
      printf("
");
   }
   // Prints lower part of the arrow
   for (i = 2; i <= num; i++) {
      // to print the spaces
      for (j = 1; j < i; j++) {
         printf(" ");
      }
      // to print the * for the pattern
      for (j = 1; j <= i; j++) {
         printf("*");
      }
      printf("
");
   }
   return 0;
}
int main() {
   // get the value from user
   int num = 4;
   // function calling
   arrow(num);
   return 0;
}

Output

If run the above code it will generate the following output −