Print the given pattern recursively
Given a positive integer n. Print the inverted triangular pattern (as described in the examples below) using the recursive approach.
Examples:
Input : n = 5 Output : * * * * * * * * * * * * * * * Input : n = 7 Output : * * * * * * * * * * * * * * * * * * * * * * * * * * * *
Method 1 (Using two recursive functions): One recursive function is used to get the row number and the other recursive function is used to print the stars of that particular row.
Algorithm:
printPatternRowRecur(n)
if n < 1
return
print "* "
printPatternRowRecur(n-1)
printPatternRecur(n)
if n < 1
return
printPatternRowRecur(n)
print "\n"
printPatternRecur(n-1)
C++
// C++ implementation to print the given // pattern recursively #include <bits/stdc++.h> using namespace std; // function to print the 'n-th' row of the // pattern recursively void printPatternRowRecur(int n) { // base condition if (n < 1) return; // print the remnaining stars of the n-th row // recursively cout << "* "; printPatternRowRecur(n-1); } void printPatternRecur(int n) { // base condition if (n < 1) return; // print the stars of the n-th row printPatternRowRecur(n); // move to next line cout << endl; // print stars of the remaining rows recursively printPatternRecur(n-1); } // Driver program to test above int main() { int n = 5; printPatternRecur(n); return 0; } |
Java
// java implementation to print the given // pattern recursively import java.io.*; class GFG { // function to print the 'n-th' row // of the pattern recursively static void printPatternRowRecur(int n) { // base condition if (n < 1) return; // print the remnaining stars // of the n-th row recursively System.out.print( "* "); printPatternRowRecur(n - 1); } static void printPatternRecur(int n) { // base condition if (n < 1) return; // print the stars of the n-th row printPatternRowRecur(n); // move to next line System.out.println (); // print stars of the // remaining rows recursively printPatternRecur(n - 1); } // Driver program to test above public static void main (String[] args) { int n = 5; printPatternRecur(n); } } //This code is contributed by vt_m |
Python3
# Python 3 implementation # to print the given # pattern recursively # function to print the # 'n-th' row of the # pattern recursively def printPatternRowRecur(n): # base condition if (n < 1): return # print the remnaining # stars of the n-th row # recursively print("*", end = " ") printPatternRowRecur(n - 1) def printPatternRecur(n): # base condition if (n < 1): return # print the stars of # the n-th row printPatternRowRecur(n) # move to next line print("") # print stars of the # remaining rows recursively printPatternRecur(n - 1) # Driver Code n = 5printPatternRecur(n) # This code is contributed # by Smitha |
C#
// C# implementation to print the given // pattern recursively using System; class GFG { // function to print the 'n-th' row // of the pattern recursively static void printPatternRowRecur(int n) { // base condition if (n < 1) return; // print the remnaining stars // of the n-th row recursively Console.Write( "* "); printPatternRowRecur(n - 1); } static void printPatternRecur(int n) { // base condition if (n < 1) return; // print the stars of the n-th row printPatternRowRecur(n); // move to next line Console.WriteLine(); // print stars of the // remaining rows recursively printPatternRecur(n - 1); } // Driver program to test above public static void Main() { int n = 5; printPatternRecur(n); } } //This code is contributed by vt_m |
PHP
<?php // php implementation to print the given // pattern recursively // function to print the 'n-th' row // of the pattern recursively function printPatternRowRecur($n) { // base condition if ($n < 1) return; // print the remnaining stars of // the n-th row recursively echo "* "; printPatternRowRecur($n-1); } function printPatternRecur($n) { // base condition if ($n < 1) return; // print the stars of the n-th row printPatternRowRecur($n); // move to next line echo "\n"; // print stars of the remaining // rows recursively printPatternRecur($n-1); } // Driver code $n = 5; printPatternRecur($n); // This code is contributed by mits ?> |
Output:
* * * * * * * * * * * * * * *
Method 2 (Using single recursive function): This approach uses a single recursive function to print the entire pattern.
Algorithm:
printPatternRecur(n, i)
if n < 1
return
if i <= n
print "* "
printPatternRecur(n, i+1)
else
print "\n"
printPatternRecur(n-1, 1)
C++
// C++ implementation to print the given pattern recursively #include <bits/stdc++.h> using namespace std; // function to print the given pattern recursively void printPatternRecur(int n, int i) { // base condition if (n < 1) return; // to print the stars of a particular row if (i <= n) { cout << "* "; // recursively print rest of the stars // of the row printPatternRecur(n, i + 1); } else { // change line cout << endl; // print stars of the remaining rows recursively printPatternRecur(n-1, 1); } } // Driver program to test above int main() { int n = 5; printPatternRecur(n, 1); return 0; } |
Java
// java implementation to // print the given pattern recursively import java.io.*; class GFG { // function to print the // given pattern recursively static void printPatternRecur(int n, int i) { // base condition if (n < 1) return; // to print the stars of // a particular row if (i <= n) { System.out.print ( "* "); // recursively print rest // of the stars of the row printPatternRecur(n, i + 1); } else { // change line System.out.println( ); // print stars of the // remaining rows recursively printPatternRecur(n - 1, 1); } } // Driver program public static void main (String[] args) { int n = 5; printPatternRecur(n, 1); } } // This code is contributed by vt_m |
Python 3
# Python3 implementation to print the # given pattern recursively # function to print the given pattern # recursively def printPatternRecur(n, i): # base condition if (n < 1): return # to print the stars of a # particular row if (i <= n): print("* ", end = "") # recursively print rest of # the stars of the row printPatternRecur(n, i + 1) else: # change line print("") # print stars of the remaining # rows recursively printPatternRecur(n-1, 1) # Driver program to test above n = 5printPatternRecur(n, 1) # This code is contributed by Smitha |
C#
// C# implementation to // print the given pattern recursively using System; class GFG { // function to print the // given pattern recursively static void printPatternRecur(int n, int i) { // base condition if (n < 1) return; // to print the stars of // a particular row if (i <= n) { Console.Write ( "* "); // recursively print rest // of the stars of the row printPatternRecur(n, i + 1); } else { // change line Console.WriteLine( ); // print stars of the // remaining rows recursively printPatternRecur(n - 1, 1); } } // Driver program public static void Main () { int n = 5; printPatternRecur(n, 1); } } // This code is contributed by vt_m |
PHP
<?php // php implementation to print // the given pattern recursively // function to print the given // pattern recursively function printPatternRecur($n, $i) { // base condition if ($n < 1) return; // to print the stars of // a particular row if ($i <= $n) { echo "* "; // recursively print rest of // the stars of the row printPatternRecur($n, $i + 1); } else { // change line echo "\n"; // print stars of the remaining // rows recursively printPatternRecur($n - 1, 1); } } // Driver code $n = 5; printPatternRecur($n, 1); // This code is contributed by mits ?> |
Output:
* * * * * * * * * * * * * * *
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