I'm trying to create an nxn vector that I can later cout
as a table/matrix. Xcode points to the =
in the for
loop and tells me No viable overloaded '='
. I don't know what that means or how to fix it.
int n=5;
vector< vector<int> > row(n);
for (int i=0; i<n; i++) {
row[i] = new vector<int> column(n);
}
Also tried this, but Xcode didn't like it either and this time pointed to column
and said Expected ')'
:
int n=5;
vector< vector<int> > row;
for (int i=0; i<n; i++) {
row.push_back(new vector<int> column(n));
}
My guess is that it has something to do with the way I'm declaring the new vector column
inside the for
loop. Any help/advice is much appreciated. Thanks.
The simple solution is to use the relevant constructor of std::vector
, initializing it to n
elements each having the value of val
- no loops necessary.
std::vector<T> (n, val);
Having your original snippet we would end up with the following, which will initialize row to have n
std::vector s, each of which having n
elements.
std::vector<std::vector<int> > row (n, std::vector<int> (n));
Try the following
int n = 5;
std::vector< std::vector<int> > row(n);
for (int i=0; i<n; i++) {
row[i].push_back( std::vector<int>(n) );
}
or
int n = 5;
std::vector< std::vector<int> > row(n, std::vector<int>( n ) );
When the constructor of row
is called, all elements are initialized too. I think this code does what you're looking to do:
for (int i=0; i<n; i++) {
row[i].resize(n);
}
Now all elements of row will be of size n
.
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