How to create patterns in c++ language?

 

Nested loop in c++:

To  study the nested for loop click on the following link: nested loop

How to create pattrens:

Example 1: Program to Print a Half-Pyramid Using *

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

Source Code:

#include <iostream>
using namespace std;

int main() {

    int rows;

    cout << "Enter number of rows: ";
    cin >> rows;

    for(int i = 1; i <= rows; ++i) {
        for(int j = 1; j <= i; ++j) {
            cout << "* ";
        }
        cout << "\n";
    }
    return 0;
}

---

Example 2: Program to Print a Half-Pyramid Using Numbers

1
1 2
1 2 3
1 2 3 4
1 2 3 4 5

Source Code:

#include <iostream>
using namespace std;

int main() {

    int rows;

    cout << "Enter number of rows: ";
    cin >> rows;

    for(int i = 1; i <= rows; ++i) {
        for(int j = 1; j <= i; ++j) {
            cout << j << " ";
        }
        cout << "\n";
    }
    return 0;
}

---

Example 3: Program to Print Half-Pyramid Using Alphabets

A
B B
C C C
D D D D
E E E E E

Source Code:

#include <iostream>
using namespace std;

int main() {

    char input, alphabet = 'A';

    cout << "Enter the uppercase character you want to print in the last row: ";
    cin >> input;

    // convert input character to uppercase
    input = toupper(input);

    for(int i = 1; i <= (input-'A'+1); ++i) {
        for(int j = 1; j <= i; ++j) {
            cout << alphabet << " ";
        }
        ++alphabet;

        cout << endl;
    }
    return 0;
}

---

Programs to Print an Inverted Half-Pyramid Using * and Numbers:

Example 4: Inverted Half-Pyramid Using *

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

Source Code:

#include <iostream>
using namespace std;

int main() {

    int rows;

    cout << "Enter number of rows: ";
    cin >> rows;

    for(int i = rows; i >= 1; --i) {
        for(int j = 1; j <= i; ++j) {
            cout << "* ";
        }
        cout << endl;
    }
    
    return 0;
}

---

Example 5: Inverted Half-Pyramid Using Numbers

1 2 3 4 5
1 2 3 4 
1 2 3
1 2
1

Source Code:

#include <iostream>
using namespace std;

int main() {

    int rows;

    cout << "Enter number of rows: ";
    cin >> rows;

    for(int i = rows; i >= 1; --i)
    {
        for(int j = 1; j <= i; ++j)
        {
            cout << j << " ";
        }
        cout << endl;
    }

    return 0;
}

---

Programs to Display Pyramids and Inverted Pyramids Using * and Digits:

Example 6: Program to Print a Full Pyramid Using *

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

Source Code:

#include <iostream>
using namespace std;

int main() {

    int space, rows;

    cout <<"Enter number of rows: ";
    cin >> rows;

    for(int i = 1, k = 0; i <= rows; ++i, k = 0) {
        for(space = 1; space <= rows-i; ++space) {
            cout <<"  ";
        }

        while(k != 2*i-1) {
            cout << "* ";
            ++k;
        }
        cout << endl;
    }    
    return 0;
}

---

Example 7: Program to Print a Pyramid Using Numbers

        1
      2 3 2
    3 4 5 4 3
  4 5 6 7 6 5 4
5 6 7 8 9 8 7 6 5

Source Code:

#include <iostream>
using namespace std;

int main() {

    int rows, count = 0, count1 = 0, k = 0;

    cout << "Enter number of rows: ";
    cin >> rows;

    for(int i = 1; i <= rows; ++i) {
        for(int space = 1; space <= rows-i; ++space) {
            cout << "  ";
            ++count;
        }

        while(k != 2*i-1) {
            if (count <= rows-1) {
                cout << i+k << " ";
                ++count;
            }
            else {
                ++count1;
                cout << i+k-2*count1 << " ";
            }
            ++k;
        }
        count1 = count = k = 0;

        cout << endl;
    }
    return 0;
}

---

Example 8: Inverted Full Pyramid Using *

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

Source Code:

#include <iostream>
using namespace std;

int main() {

    int rows;

    cout << "Enter number of rows: ";
    cin >> rows;

    for(int i = rows; i >= 1; --i) {
        for(int space = 0; space < rows-i; ++space)
            cout << "  ";

        for(int j = i; j <= 2*i-1; ++j)
            cout << "* ";

        for(int j = 0; j < i-1; ++j)
            cout << "* ";

        cout << endl;
    }

    return 0;
}

---

Example 9: Print Pascal's Triangle

           1
         1   1
       1   2   1
     1   3   3    1
   1  4    6   4   1
 1  5   10   10  5   1 

Source Code:

#include <iostream>
using namespace std;

int main() {

    int rows, coef = 1;

    cout << "Enter number of rows: ";
    cin >> rows;

    for(int i = 0; i < rows; i++) {
        for(int space = 1; space <= rows-i; space++)
            cout <<"  ";

        for(int j = 0; j <= i; j++) {
            if (j == 0 || i == 0)
                coef = 1;
            else
                coef = coef*(i-j+1)/j;

            cout << coef << "   ";
        }
        cout << endl;
    }

    return 0;
}

---

Example 10: Print Floyd's Triangle.

1
2 3
4 5 6
7 8 9 10

Source Code:

#include <iostream>
using namespace std;

int main() {

    int rows, number = 1;

    cout << "Enter number of rows: ";
    cin >> rows;

    for(int i = 1; i <= rows; i++) {
        for(int j = 1; j <= i; ++j) {
            cout << number << " ";
            ++number;
        }

        cout << endl;
    }

    retern 0;