mirror of https://github.com/davisking/dlib.git
48 lines
2.0 KiB
C++
Executable File
48 lines
2.0 KiB
C++
Executable File
// The contents of this file are in the public domain. See LICENSE_FOR_EXAMPLE_PROGRAMS.txt
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/*
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This simple example shows how to call dlib's optimal linear assignment problem solver.
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It is an implementation of the famous Hungarian algorithm and is quite fast, operating in
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O(N^3) time.
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*/
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#include <dlib/optimization/max_cost_assignment.h>
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#include <iostream>
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using namespace std;
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using namespace dlib;
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int main ()
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{
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// Let's imagine you need to assign N people to N jobs. Additionally, each person will make
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// your company a certain amount of money at each job, but each person has different skills
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// so they are better at some jobs and worse at others. You would like to find the best way
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// to assign people to these jobs. In particular, you would like to maximize the amount of
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// money the group makes as a whole. This is an example of an assignment problem and is
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// what is solved by the max_cost_assignment() routine.
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//
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// So in this example, let's imagine we have 3 people and 3 jobs. We represent the amount of
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// money each person will produce at each job with a cost matrix. Each row corresponds to a
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// person and each column corresponds to a job. So for example, below we are saying that
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// person 0 will make $1 at job 0, $2 at job 1, and $6 at job 2.
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matrix<int> cost(3,3);
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cost = 1, 2, 6,
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5, 3, 6,
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4, 5, 0;
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// To find out the best assignment of people to jobs we just need to call this function.
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std::vector<long> assignment = max_cost_assignment(cost);
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// This prints optimal assignments: [2, 0, 1] which indicates that we should assign
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// the person from the first row of the cost matrix to job 2, the middle row person to
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// job 0, and the bottom row person to job 1.
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for (unsigned int i = 0; i < assignment.size(); i++)
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cout << assignment[i] << std::endl;
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// This prints optimal cost: 16.0
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// which is correct since our optimal assignment is 6+5+5.
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cout << "optimal cost: " << assignment_cost(cost, assignment) << endl;
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}
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