int minPath(vector<vector<int>> &triangle, pair<int, int>& cell, map<pair<int, int>, int> &scratch)
{
if (cell.first == (triangle.size() - 1))
{
return triangle[cell.first][cell.second];
}
if (scratch.count(cell) == 0)
{
scratch[cell] = min(minPath(triangle, pair<int, int>(cell.first + 1, cell.second), scratch), minPath(triangle, pair<int, int>(cell.first + 1, cell.second + 1), scratch)) + triangle[cell.first][cell.second];
}
return scratch[cell];
}
//OpenMP Implementation of Dijkstra's Algorithm
void DijkstraOMP(Vertex *vertices, Edge *edges, int *weights, Vertex *root)
{
double start, end;
root->visited = TRUE;
int len[V];
len[(int)root->title] = 0;
int i, j;
for(i = 0; i < V;i++)
{
if(vertices[i].title != root->title)
{
len[(int)vertices[i].title] = findEdge(*root, vertices[i], edges, weights);
}
else{
vertices[i].visited = TRUE;
}
}
start = omp_get_wtime();
for(j = 0; j < V; j++){
Vertex u;
int h = minPath(vertices, len);
u = vertices[h];
//OpenMP Parallelization Starts here!!!
#pragma omp parallel for schedule(runtime) private(i)
for(i = 0; i < V; i++)
{
if(vertices[i].visited == FALSE)
{
int c = findEdge( u, vertices[i], edges, weights);
len[vertices[i].title] = minimum(len[vertices[i].title], len[u.title] + c);
}
}
}
end = omp_get_wtime();
printArray(len);
printf("Running time: %f ms\n", (end - start)*1000);
}
int topDown(vector<vector<int>> &triangle)
{
map<pair<int, int>, int> scratch;
return minPath(triangle, pair<int, int>( 0, 0 ), scratch);
}
