filling an area of a matrix with characters - c++

Question

I have created a matrix using 2D vectors. The code I used is
int RC=50;
vector<vector<int> > matrix;
vector<int>row;
///////////Building Grid//////////////////
for(int i=0;i<RC;i++)
{
for(int j=0;j<RC;j++)
{
row.push_back(0);
}
matrix.push_back(row);
}
//////////Printing Grid///////////////////
for(int i=0;i<RC;i++)
{
for(int j=0;j<RC;j++)
{
cout<<matrix[i][j]<<" ";
}
cout<<endl;
}
The output of the above code is
Now what I want is to fill a block of size 6x6 inside the matrix with '$' or any character by inputting the bottom left location of the block. For example if i gave the location as (10,4), then I would like to place a block of '$' (size 6x6) whose bottom left co-ordinates are (10,4).
EDIT-1
I added the code
int si=3;
int sy=3;
for(int i=0;i<RC;i++)
{
for(int j=0;j<RC;j++)
{
if(i>=si && i<=si+6 && j>=sy && j<=sy+6)
{
matrix[i][j]=1;
}
else
{
matrix[i][j]=0;
}
}
}
and I got the output as
I am reading the co-ordinates as the top left ones, what should I do to read the co-ordinates as the bottom left ones and build the block from there?

Answer 1

You need to tackle the problem logically and break down the steps you need to solve it. You're staring at a big block of zeros and that isn't going to help. So, walk through it with pseudo code and a handy, dandy piece of paper and pencil.
Ask smaller questions about the larger problem at hand. How do you go from bottom left coordinate to the coordinate you wish to start with? How do you determine when to stop? Do I understand what I just did? If not why don't I understand it?
Baby step by baby step while you're learning. Take the time to understand why something either worked the way you wanted it to or failed to work. Do this and you'll be a much better coder for it.