使用WHILE循环的直角三角形的C ++代码

Question

I need to print this triangle:

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

using a FOR and WHILE loop. I need help, I have already figured out the for loop version I just have to convert it to while loop but everything I try is not giving me the correct output! Any help is appreciated!

My code so far:

#include <iostream>
using namespace std;
int main(int argc, char**argv) {

    int i = 1;
    int j = 1;
    int N = 8;

    while (i <= N)
    {
        i = i++;
        while(j <= i)
        {
            cout<<"*";
            j = j++;
        }
        cout<<endl;
    }
}

Answer 1

I'll give you a hint (in the interest of making you do some figuring out yourself): You're forgetting to set j back to 1 after the inner loop.

As it is now, when j gets to be <= i once, it stays that way and the inner loop is never entered again.

---

Also, while it's not directly related to your question, make sure never to do j = j++ or i = i++ ; just do j++ and i++ (as Kshitij Mehta said in the comments). If you're interested in why, you can read this question and its answers .

Answer 2

I'll give you a hint as well: i = i++; doesn't do what you think it does.

Answer 3

What are the rules?

while (1)
{
    cout << "*" << '\n';
    cout << "**" << '\n';
    cout << "***" << '\n';
    cout << "****" << '\n';
    cout << "*****" << '\n';
    cout << "******" << '\n';
    cout << "*******" << '\n';
    cout << "********" << '\n';

    break;
}

Answer 4

I can't see your triangle, but I think you need to set j to 1 before each loop on j:

while (i <= N)
{
    i++;
    j = 1;
    while(j <= i)
    {
        cout<<"*";
        j++;
    }
    cout<<endl;
}

Answer 5

I don't really know how to make it more succinct than this:

#include <iostream>
#include <sstream>

int main()
{
    std::stringstream ss;
    int i = 10;
    while (i--)
        std::cout << (ss<<'*', ss).str() << std::endl;
}

or as for loop, cutting down a line

for(int i=10; i--;)
        std::cout << (ss<<'*', ss).str() << std::endl;

---

If you don't mind some less efficient code:

#include <iostream>
int main() { for(int i=1; i<10; std::cout << std::string(i++, '*') << std::endl); }

Answer 6

#include <iostream>   

using namespace std;    

int main() 
{
    int i, j, N=7;  
    while(i <= N)
    {  
        i++;  
        j = 1;  
        while(j <= i)
        {
            cout << "*";  
            j++;
        }
        cout << endl;  
    }  
}