Printing a hollow right-triangle - c++

Question

I'm having issues with this c++ code. It is supposed to print a hollow right isosceles triangle, but instead just prints asterisks over and over, so the for loops seem to be stuck.
#include "pch.h"
#include <string>
#include <iostream>
int main() {
int row;
std::string s = " ";
std::string a = " *";
int rows = 10;
for (int i = 0; i < rows; i++) {
if (i = 0) {
std::cout << a << std::endl;
}
while (i > 2 && i < rows) {
std::cout << a;
for (int pos = 0; pos < i; pos++) {
std::cout << s;
}
std::cout << a << std::endl;
}
std::cout << a << a << a << a << a << a << a << a << a << std::endl;
}
}

Answer 1

your while loop condition will never become false, AND you need to use comparison (==) instead of assignment in this line:
if (i = 0) {

Answer 2

Supposing that what you want to print is something of the following form:
Eg. for rows = 5
*
**
* *
* *
*****
Your code should have the following structure:
for (int i = 1; i <= rows; ++i)
{
//special case for the first line
if (i == 1)
std::cout << asterisk << std::endl;
//for each of the other lines print 2 asterisks and the rest spaces
if (i > 1 && i <= rows - 1)
{
//one at the start of the line
std::cout << asterisk;
//print line - 2 spaces
for (int j = 0; j < i - 2; ++j)
std::cout << space;
//one at the end of the line
std::cout << asterisk << std::endl;
}
//special case for the last line
if (i == rows)
{
for (int j = 1; j <= i; ++j )
std::cout << asterisk;
std::cout << endl;
}
}
https://ideone.com/peGRUG

Answer 3

Your while loop condition is the issue here, also you should use == instead of = inside if condition. Anyways,Here is a small fix in your solution..
void printTriangle() {
int row;
std::string s = " ";
std::string a = " *";
int rows = 10;
for (int i = 1; i < rows-1; i++) {
for (int j = 1; j <= i; ++j)
{
if (j == 1 || j == i)
std::cout << a;
else
std::cout << s;
}
std::cout << std::endl;
}
for (int i = 1; i < rows; ++i)
std::cout << a;
}