mosesdecoder/moses/FloydWarshall.cpp
2012-11-12 19:56:18 +00:00

37 lines
895 B
C++

#include "util/check.hh"
#include <climits>
#include <vector>
#define MAX_DIST (INT_MAX / 2)
//#include "FloydWarshall.h"
using namespace std;
// All-pairs shortest path algorithm
void floyd_warshall(const std::vector<std::vector<bool> >& edges, std::vector<std::vector<int> >& dist)
{
CHECK(edges.size() == edges.front().size());
dist.clear();
dist.resize(edges.size(), std::vector<int>(edges.size(), 0));
size_t num_edges = edges.size();
for (size_t i=0; i<num_edges; ++i) {
for (size_t j=0; j<num_edges; ++j) {
if (edges[i][j])
dist[i][j] = 1;
else
dist[i][j] = MAX_DIST;
if (i == j) dist[i][j] = MAX_DIST;
}
}
for (size_t k=0; k<num_edges; ++k)
for (size_t i=0; i<num_edges; ++i)
for (size_t j=0; j<num_edges; ++j)
if (dist[i][j] > (dist[i][k] + dist[k][j]))
dist[i][j] = dist[i][k] + dist[k][j];
}