MaxFlowDinic/README.md

# Max Flow using Dinic's Algorithm

## Installation

This project does not have any specific requirements other than a cpp compiler. The installations process follows the CMake procedure:

```
git clone https://git.pranger.xyz/sp/MaxFlowDinic
cd MaxFlowDinic
mkdir build
cd build
cmake .. && make
```

## Usage

To display the help message:

```
> ./build/maxFlow -h

You need to pass either and input graph file or an input graph string.
Allowed options:
  -h, --help              Print this help message.
  -f, --input-file arg    Filename of input graph file.
  -s, --input-string arg  Input graph string.
  -o, --stdout            Output to stdout.
  -p, --output-file arg   Filename for output.
  -a, --max-flow          Include verbose information about the max flow to the output.
  -m, --minimum-cut       Include the minimum cut set to the output.
  -v, --verbose           Output verbose algorithmic information and runtime. Pass twice to get information about all augmenting paths computed.
```

The examples folder features a few toy examples. Using the `-f` option to pass the path to an input file and `-mavv` gives a verbose output.

For example:
```
>./build/maxFlow -f examples/1.txt -mavv
#Vertices: 10
#Arc: 14
Source: 1, Sink: 10
Vertices: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
  1 -> 2 capacity = 5
  2 -> 10 capacity = 4
  1 -> 10 capacity = 7
  1 -> 3 capacity = 8
  3 -> 10 capacity = 9
  1 -> 4 capacity = 3
  4 -> 7 capacity = 1
  7 -> 10 capacity = 1
  1 -> 5 capacity = 3
  5 -> 8 capacity = 4
  8 -> 10 capacity = 6
  1 -> 6 capacity = 7
  6 -> 9 capacity = 6
  9 -> 10 capacity = 5
Found max flow |x| = 28
Max Flow per arc:
  1 -> 2 flow = 4/5
  2 -> 10 flow = 4/4
  1 -> 10 flow = 7/7
  1 -> 3 flow = 8/8
  3 -> 10 flow = 8/9
  1 -> 4 flow = 1/3
  4 -> 7 flow = 1/1
  7 -> 10 flow = 1/1
  1 -> 5 flow = 3/3
  5 -> 8 flow = 3/4
  8 -> 10 flow = 3/6
  1 -> 6 flow = 5/7
  6 -> 9 flow = 5/6
  9 -> 10 flow = 5/5
Min Cut X: {1, 2, 4, 6, 9}
Complement(X): {3, 5, 7, 8, 10}
Elapsed time: 1ms (1046µs).
Computation Statistics:
  #level graphs built: 4
  #augmenting paths computed: 6
    1 > 10 | flow = 7
    1 > 2 > 10 | flow = 4
    1 > 3 > 10 | flow = 8
    1 > 4 > 7 > 10 | flow = 1
    1 > 5 > 8 > 10 | flow = 3
    1 > 6 > 9 > 10 | flow = 5
  #recursive buildPath calls: 32
```