Number Pattern in C++

Number triangle in C++: row i prints 1..i. Same loops as the right-half pyramid, j instead of *.

BeginnerPattern ProgramsExample 5 of 6

number-pattern.cpp

1#include <iostream>
2using namespace std;
3
4int main() {
5    int rows;
6    
7    cout << "Enter number of rows: ";
8    cin >> rows;
9    
10    for (int i = 1; i <= rows; i++) {
11        for (int j = 1; j <= i; j++) {
12            cout << j << " ";
13        }
14        cout << endl;
15    }
16    
17    return 0;
18}

Output

Enter number of rows: 5
1
1 2
1 2 3
1 2 3 4
1 2 3 4 5

What's going on

Same nested shape as the right-half pyramid, but print j instead of *. Row i prints 1 2 … i.

for (int i = 1; i <= rows; i++)

for (int j = 1; j <= i; j++)

cout << j << " ";

Walk 5:

i=1: 1

i=2: 1 2

i=3: 1 2 3

i=4: 1 2 3 4

i=5: 1 2 3 4 5

cout << i instead of j and every row is the same digit: 1 / 22 / 333 / … That's a different homework.

j from i down to 1 prints 5 4 3 2 1 on the last row.

Spaces and centering are the left-half / full-pyramid trick. This program doesn't pad.

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