I have this algorithm that is pseudocode for the dijkstra algorithm for graph theory. The first thing that goes on is a basic for loop.
visitedSet[0] = true //visitedSet is a array of bools
for (int i = 1; i <= numberNodes; ++i)
{
distanceArray[i] = adjacencyMatrix[0,i];
//distanceArray is 1D with size of fifty
//adjacencyMatrix is 2D with size of fifty
//Both arrays hold values of unsigned ints
}
Here are the array definitions
enum GraphLimit300 {MAX_NODES = 50};
unsigned int adjacencyMatrix[MAX_NODES][MAX_NODES];
unsigned int distanceArray[MAX_NODES];
Visual studio is giving me an array saying that I can't assign an array of unsigned integers to a pointer. I have looked up online that with the comma operator basically in this case throws out the first case, 0
, and treats it as distanceArray[i] = adjacencyMatrix[i];
Which doesn't make sense to me since adjacenyMatrix
is a 2D array. I am just wondering what is giving me this compile error and get more information on why, because I basically just copying in variable names where the pseudo code basically says to.
Pseudo code:
S = { 1 }
for ( index = 2; index <= N; ++ index )
D[ index ] = C[ 1, index ]
for ( index = 1; index <= N – 1; ++ index )
Choose a vertex v in V – S such that D[ v ] is a minimum
Add v to S
for each vertex w in V – S do
D[ w ] = min( D[ w ], D[ v ] + C[ v, w ] )
The above pseudo code uses lists to represent their arrays they for some reason start at 1 so I modified it to start at 0 in my code.
You have to review how to access elements of 2D array. Also, take look at what comma operator does. You have to use []
twice:
adjacencyMatrix[0][i]
The following:
adjacencyMatrix[0, i]
is equivalent to:
adjacencyMatrix[i]
Which will still leave you with 1D array. And, as the error message says:
distanceArray[i] = adjacencyMatrix[i];
// ^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^
// unsigned int array of unsigned ints
You can not possibly expect this assignment to happen.
来源:https://stackoverflow.com/questions/34098166/comma-operator-with-indexing-2d-arrays