Support cases with rows != cols

[Nuzhny007]

Hi!
Thnx for this very useful project!
I'm working on problem Multiple objects tracking where solve linear assignment task with Hungarian algorithm. But your method must be faster on big N. But cost matrices on tracking isn't square - they are rectangular: detects are more then tracks or tracks more then detects.
So I make some changes in your project for my task. You can see they here: Nuzhny007@db85d1e

If my changes may be useful for you then can I create pull request. So, what do think about it?

[Rainy000]

you can expand it into a square matrix and calculate again, the turth result can be get after filter the raw result.
sample code:

// Notice that col, row, cost these types are typedef-ed in lap.h
int M = data.size();        // Set the dimension of matrix to 10, dim is the problem size
int N = data[0].size();
int max_dim = M > N ? M : N;

cost ** costMatrix;    // A matrix to store all the costs from vertex i to vertex j
col *rowsol;         // An array to store column indexes assigned to row in solution  
row *colsol;         // An array to store row indexes assigned to column in solution 
cost *u;             // u          - dual variables, row reduction numbers
cost *v;             // v          - dual variables, column reduction numbers
rowsol = new col[max_dim];
colsol = new row[max_dim];
u = new cost[max_dim];
v = new cost[max_dim];
costMatrix = new cost*[max_dim];
for(int i=0;i<max_dim;i++){
    costMatrix[i]  =  new cost[max_dim];
}
// Assign costs to the costMatrix
for(int i=0; i<max_dim; ++i){
    for(int j=0; j<max_dim; ++j){
        if (i < M&& j < N)
            costMatrix[i][j]  =  atof(data[i][j].c_str());
        else
            costMatrix[i][j]  = BIG;
    }
}
cost totalCost = lap(max_dim, costMatrix, rowsol, colsol, u, v);  // Use lap algorithm to calculate the minimum total cost
// Output lap result to a file
std::cout<<"The total cost is: "<<totalCost<<std::endl;
std::cout<<"The match infos: "<<std::endl;
for(int i=0; i< max_dim; i++){
    if (i < M && rowsol[i] < N)
        std::cout<<"r:"<<i<<"\tc:"<<rowsol[i]<<std::endl;
    else{
        continue;
    }
}