1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
#include <cusp/csr_matrix.h>
#include <cusp/print.h>
#include <cusp/gallery/grid.h>
#include <cusp/graph/maximum_flow.h>
#include <cusp/io/matrix_market.h>
#include "../timer.h"
template<typename MemorySpace, typename MatrixType>
void MaxFlow(const MatrixType& G)
{
typedef typename MatrixType::index_type IndexType;
typedef typename MatrixType::value_type ValueType;
typedef cusp::csr_matrix<IndexType,ValueType,MemorySpace> GraphType;
GraphType G_flow(G);
cusp::array1d<IndexType,MemorySpace> min_cut_edges(G.num_entries);
cusp::array1d<ValueType,MemorySpace> flow(G.num_entries);
IndexType source = 0;
IndexType sink = G.num_rows - 1;
{
timer t;
ValueType capacity = cusp::graph::maximum_flow(G_flow, flow, source, sink);
std::cout << "Max-Flow time : " << t.milliseconds_elapsed() << " (ms), with capacity : " << capacity << std::endl;
}
{
timer t;
size_t min_cut_size = cusp::graph::max_flow_to_min_cut(G_flow, flow, source, min_cut_edges);
std::cout << "\tMin-Cut time : " << t.milliseconds_elapsed() << " (ms), found " << min_cut_size << " edge cuts." << std::endl;
}
}
int main(int argc, char*argv[])
{
srand(time(NULL));
typedef int IndexType;
typedef int ValueType;
typedef cusp::host_memory MemorySpace;
cusp::csr_matrix<IndexType, ValueType, MemorySpace> A;
size_t size = 4;
if (argc == 1)
{
// no input file was specified, generate an example
std::cout << "Generated matrix (2D Grid) ";
cusp::gallery::grid2d(A, size, size);
}
else if (argc == 2)
{
// an input file was specified, read it from disk
cusp::io::read_matrix_market_file(A, argv[1]);
std::cout << "Read matrix (" << argv[1] << ") ";
}
std::cout << "with shape (" << A.num_rows << "," << A.num_cols << ") and "
<< A.num_entries << " entries" << "\n\n";
// Generate random capacities in range [4,100)
for( size_t index = 0; index < A.num_entries; index++ )
A.values[index] = (rand() % 100) + 4;
std::cout << " Device ";
MaxFlow<cusp::device_memory>(A);
std::cout << " Host ";
MaxFlow<cusp::host_memory>(A);
std::cout << std::endl;
return EXIT_SUCCESS;
}
|
