C++ Program To Print Inverted Hollow Star Pyramid Pattern
Last Updated :
05 Jul, 2022
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Given the value of R(number of rows), write a C++ program to print the Inverted Hollow Pyramid using stars and white spaces.
Examples:
Input: R = 5
Output:
*********
* *
* *
* *
*
Input: R = 10
Output:
*******************
* *
* *
* *
* *
* *
* *
* *
* *
*
Algorithm:
- At first, take the number of rows as input.
- The next step is to implement the nested loop to print this pattern.
- A space-maintaining variable(sp) is required to maintain the space at the beginning.
- Calculate the last column by Last Column = (length _of_row * 2 - (2 * Current_row - 1))
- Print star( "*" ) at the first column and last column and proceed to the next row.
Below is the C++ program to implement the above approach:
// C++ program to Print a Inverted
// hollow Star Pyramid
#include <bits/stdc++.h>
using namespace std;
void print_patt(int R)
{
// To iterate through the rows
for(int i = 1; i <= R; i++)
{
// To print the beginning spaces
for(int sp = 1;
sp <= i - 1 ; sp++)
{
cout << " ";
}
// Iterating from ith column to
// last column (R*2 - (2*i - 1))
int last_col = (R * 2 - (2 * i - 1));
// To iterate through column
for(int j = 1; j <= last_col; j++)
{
// To Print all star for first
// row (i==1) ith column (j==1)
// and for last column
// (R*2 - (2*i - 1))
if(i == 1)
cout << "*";
else if(j == 1)
cout << "*";
else if(j == last_col)
cout << "*";
else
cout << " ";
}
// After printing a row proceed
// to the next row
cout << "\n";
}
}
// Driver code
int main()
{
// Number of rows
int R = 5;
print_patt(R);
return 0;
}
Output
*********
* *
* *
* *
*Time Complexity: O(R*last_col), where R represents the row and last_col represents the last column.
Auxiliary Space: O(1), no extra space is required, so it is a constant.
