What is wrong with my code?

[DeezyM89]

I have an issue with my code. When R1>R2 and C1>C2 it doesn't work, but if R1<R2 and C1<C2 it runs correctly. this is my code:

#include <iostream>
#include <iomanip>

using namespace std;

int main()
{
    int R1, R2, C1, C2;
    int col;

    cout << "Please Enter Four Integers R1 R2 C1 C2: ";
    cin>>R1>>R2>>C1>>C2;
    cout<<R1<<" "<<R2<<" "<<C1<<" "<<C2<<endl;
    
    if(R1<R2 & C1<C2)
    {
        
    }
    
    cout<< endl << "        ";
    for(col = C1; col <= C2; col++)
   
    cout << left << setw(6) << col;
    cout << endl;
    cout << "-----";

    for(col = C1; col <= C2; col++)
    cout << "|-----";
    cout << "|" << endl;

    for(; R1<=R2; R1++)
    {
        cout << left << setw(7) << R1;
        for(col = C1; col <= C2; col++)
        cout << left << setw(6) << R1*col;
        cout << endl << "-----";
        for(col = C1; col <= C2; col++)
        cout << "|-----";
        cout << "|" << endl;
    }


    return 0;
}

My output

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Please Enter Four Integers R1 R2 C1 C2: 0 8 5 -3

0 -----| 1 -----| 2 -----| 3 -----| 4 -----| 5 -----| 6 -----| 7 -----| 8 -----|

what it is suposed to look like:

Please Enter Four Integers R1 R2 C1 C2: 0 8 5 -3 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

5 4 3 2 1 0 -1 -2 -3

0 0 0 0 0 0 0 0 0 0 -----|-----|-----|-----|-----|-----|-----|-----|-----|-----| 1 5 4 3 2 1 0 -1 -2 -3 -----|-----|-----|-----|-----|-----|-----|-----|-----|-----| 2 10 8 6 4 2 0 -2 -4 -6 -----|-----|-----|-----|-----|-----|-----|-----|-----|-----| 3 15 12 9 6 3 0 -3 -6 -9 -----|-----|-----|-----|-----|-----|-----|-----|-----|-----| 4 20 16 12 8 4 0 -4 -8 -12 -----|-----|-----|-----|-----|-----|-----|-----|-----|-----| 5 25 20 15 10 5 0 -5 -10 -15 -----|-----|-----|-----|-----|-----|-----|-----|-----|-----| 6 30 24 18 12 6 0 -6 -12 -18 -----|-----|-----|-----|-----|-----|-----|-----|-----|-----| 7 35 28 21 14 7 0 -7 -14 -21 -----|-----|-----|-----|-----|-----|-----|-----|-----|-----| 8 40 32 24 16 8 0 -8 -16 -24 -----|-----|-----|-----|-----|-----|-----|-----|-----|-----|

can someone tell me what I am doing wrong?

[Peter87]

If R1 > R2 then the loop condition R1 <= R2 will be false right away.

If C1 > C2 and col starts as C1 then the loop condition col <= C2 will also be false.

This means the loops won't run.

[coder777]

What you can do is swap(...) the values:

    if(R2<R1) // The same for C
    {
        std::swap(R2, R1);
    }

But that depends on how you want to use them.

Another approach would be using the distance:

    const int r_dist = std::max(R1, R2) - std::min(R1, R2);
    for(int ri = 0; ri < r_dist; ++ri)
    {
        cout << left << setw(7) << R1 + ri;
    }

This would keep the order.

[salem c]

> if(R1<R2 & C1<C2)
Also note that & is the bitwise operator and && is the boolean operator.