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November 23rd, 2019, 10:33 AM
#1
convert c++ to java
Code:
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include<stdbool.h>
// // A structure to represent a node in adjacency list
struct AdjListNode
{
int dest;
int weight;
struct AdjListNode *next;
};
// A structure to represent an adjacency liat
struct AdjList
{
struct AdjListNode *head; // pointer to head node of list
};
// A structure to represent a graph. A graph is an array of adjacency lists.
// Size of array will be V (number of vertices in graph)
struct Graph
{
int V;
struct AdjList *array;
};
// A utility function to create a new adjacency list node
struct AdjListNode *
newAdjListNode (int dest, int weight)
{
struct AdjListNode *newNode =
(struct AdjListNode *) malloc (sizeof (struct AdjListNode));
newNode->dest = dest;
newNode->weight = weight;
newNode->next = NULL;
return newNode;
}
// A utility function that creates a graph of V vertices
struct Graph *
createGraph (int V)
{
struct Graph *graph = (struct Graph *) malloc (sizeof (struct Graph));
graph->V = V;
// Create an array of adjacency lists. Size of array will be V
graph->array = (struct AdjList *) malloc (V * sizeof (struct AdjList));
// Initialize each adjacency list as empty by making head as NULL
for (int i = 0; i < V; ++i)
graph->array[i].head = NULL;
return graph;
}
// Adds an edge to an undirected graph
void
addEdge (struct Graph *graph, int src, int dest, int weight)
{
// Add an edge from src to dest. A new node is added to the adjacency
// list of src. The node is added at the begining
struct AdjListNode *newNode = newAdjListNode (dest, weight);
newNode->next = graph->array[src].head;
graph->array[src].head = newNode;
// Since graph is undirected, add an edge from dest to src also
newNode = newAdjListNode (src, weight);
newNode->next = graph->array[dest].head;
graph->array[dest].head = newNode;
}
// Structure to represent a min heap node
struct MinHeapNode
{
int v;
int dist;
};
// Structure to represent a min heap
struct MinHeap
{
int size; // Number of heap nodes present currently
int capacity; // Capacity of min heap
int *pos; // This is needed for decreaseKey()
struct MinHeapNode **array;
};
// A utility function to create a new Min Heap Node
struct MinHeapNode *
newMinHeapNode (int v, int dist)
{
struct MinHeapNode *minHeapNode =
(struct MinHeapNode *) malloc (sizeof (struct MinHeapNode));
minHeapNode->v = v;
minHeapNode->dist = dist;
return minHeapNode;
}
// A utility function to create a Min Heap
struct MinHeap *
createMinHeap (int capacity)
{
struct MinHeap *minHeap =
(struct MinHeap *) malloc (sizeof (struct MinHeap));
minHeap->pos = (int *) malloc (capacity * sizeof (int));
minHeap->size = 0;
minHeap->capacity = capacity;
minHeap->array =
(struct MinHeapNode **) malloc (capacity * sizeof (struct MinHeapNode *));
return minHeap;
}
// A utility function to swap two nodes of min heap. Needed for min heapify
void
swapMinHeapNode (struct MinHeapNode **a, struct MinHeapNode **b)
{
struct MinHeapNode *t = *a;
*a = *b;
*b = t;
}
// A standard function to heapify at given idx
// This function also updates position of nodes when they are swapped.
// Position is needed for decreaseKey()
void
minHeapify (struct MinHeap *minHeap, int idx)
{
int smallest, left, right;
smallest = idx;
left = 2 * idx + 1;
right = 2 * idx + 2;
if (left < minHeap->size &&
minHeap->array[left]->dist < minHeap->array[smallest]->dist)
smallest = left;
if (right < minHeap->size &&
minHeap->array[right]->dist < minHeap->array[smallest]->dist)
smallest = right;
if (smallest != idx)
{
// The nodes to be swapped in min heap
struct MinHeapNode *smallestNode = minHeap->array[smallest];
struct MinHeapNode *idxNode = minHeap->array[idx];
// Swap positions
minHeap->pos[smallestNode->v] = idx;
minHeap->pos[idxNode->v] = smallest;
// Swap nodes
swapMinHeapNode (&minHeap->array[smallest], &minHeap->array[idx]);
minHeapify (minHeap, smallest);
}
}
// A utility function to check if the given minHeap is ampty or not
int
isEmpty (struct MinHeap *minHeap)
{
return minHeap->size == 0;
}
// Standard function to extract minimum node from heap
struct MinHeapNode *
extractMin (struct MinHeap *minHeap)
{
if (isEmpty (minHeap))
return NULL;
// Store the root node
struct MinHeapNode *root = minHeap->array[0];
// Replace root node with last node
struct MinHeapNode *lastNode = minHeap->array[minHeap->size - 1];
minHeap->array[0] = lastNode;
// Update position of last node
minHeap->pos[root->v] = minHeap->size - 1;
minHeap->pos[lastNode->v] = 0;
// Reduce heap size and heapify root
--minHeap->size;
minHeapify (minHeap, 0);
return root;
}
// Function to decreasy dist value of a given vertex v. This function
// uses pos[] of min heap to get the current index of node in min heap
void
decreaseKey (struct MinHeap *minHeap, int v, int dist)
{
// Get the index of v in heap array
int i = minHeap->pos[v];
// Get the node and update its dist value
minHeap->array[i]->dist = dist;
// Travel up while the complete tree is not hepified.
// This is a O(Logn) loop
while (i && minHeap->array[i]->dist < minHeap->array[(i - 1) / 2]->dist)
{
// Swap this node with its parent
minHeap->pos[minHeap->array[i]->v] = (i - 1) / 2;
minHeap->pos[minHeap->array[(i - 1) / 2]->v] = i;
swapMinHeapNode (&minHeap->array[i], &minHeap->array[(i - 1) / 2]);
// move to parent index
i = (i - 1) / 2;
}
}
// A utility function to check if a given vertex
// 'v' is in min heap or not
bool
isInMinHeap (struct MinHeap *minHeap, int v)
{
if (minHeap->pos[v] < minHeap->size)
return true;
return false;
}
// A utility function used to print the solution
void
printArr (int dist[], int n)
{
printf ("Vertex Distance from Source\n");
for (int i = 0; i < n; ++i)
printf ("%d \t\t %d\n", i, dist[i]);
}
// The main function that calulates distances of shortest paths from src to all
// vertices. It is a O(ELogV) function
void
dijkstra (struct Graph *graph, int src)
{
int V = graph->V; // Get the number of vertices in graph
int dist[V]; // dist values used to pick minimum weight edge in cut
// minHeap represents set E
struct MinHeap *minHeap = createMinHeap (V);
// Initialize min heap with all vertices. dist value of all vertices
for (int v = 0; v < V; ++v)
{
dist[v] = INT_MAX;
minHeap->array[v] = newMinHeapNode (v, dist[v]);
minHeap->pos[v] = v;
}
// Make dist value of src vertex as 0 so that it is extracted first
minHeap->array[src] = newMinHeapNode (src, dist[src]);
minHeap->pos[src] = src;
dist[src] = 0;
decreaseKey (minHeap, src, dist[src]);
// Initially size of min heap is equal to V
minHeap->size = V;
// In the followin loop, min heap contains all nodes
// whose shortest distance is not yet finalized.
while (!isEmpty (minHeap))
{
// Extract the vertex with minimum distance value
struct MinHeapNode *minHeapNode = extractMin (minHeap);
int u = minHeapNode->v; // Store the extracted vertex number
// Traverse through all adjacent vertices of u (the extracted
// vertex) and update their distance values
struct AdjListNode *pCrawl = graph->array[u].head;
while (pCrawl != NULL)
{
int v = pCrawl->dest;
// If shortest distance to v is not finalized yet, and distance to v
// through u is less than its previously calculated distance
if (isInMinHeap (minHeap, v) && dist[u] != INT_MAX &&
pCrawl->weight + dist[u] < dist[v])
{
dist[v] = dist[u] + pCrawl->weight;
// update distance value in min heap also
decreaseKey (minHeap, v, dist[v]);
}
pCrawl = pCrawl->next;
}
}
// print the calculated shortest distances
printArr (dist, V);
}
// Driver program to test above functions
int
main ()
{
// create the graph given in above fugure
int V = 9;
struct Graph *graph = createGraph (V);
addEdge (graph, 0, 1, 4);
addEdge (graph, 0, 7, 8);
addEdge (graph, 1, 2, 8);
addEdge (graph, 1, 7, 11);
addEdge (graph, 2, 3, 7);
addEdge (graph, 2, 8, 2);
addEdge (graph, 2, 5, 4);
addEdge (graph, 3, 4, 9);
addEdge (graph, 3, 5, 14);
addEdge (graph, 4, 5, 10);
addEdge (graph, 5, 6, 2);
addEdge (graph, 6, 7, 1);
addEdge (graph, 6, 8, 6);
addEdge (graph, 7, 8, 7);
dijkstra (graph, 0);
return 0;
}
Last edited by Arjay; November 23rd, 2019 at 10:56 AM.
Reason: Added code tags
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November 23rd, 2019, 11:01 AM
#2
Re: convert c++ to java
Please use code tags. Since you haven't asked a question, I would imagine that you might be looking for someone to write the code for you, but it is unlikely this will happen. However, if you start trying to convert the code yourself and run into specific issues, post back and we will attempt to help.
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November 23rd, 2019, 12:47 PM
#3
Re: convert c++ to java
Seems like jango is back with a new alias.
http://forums.codeguru.com/showthrea...ssignment-Help
No doubt the result of some google search and bugger all effort except to dump it here.
Oh, and just to be pedantic - you posted C code, not C++ code.
Here's another one for you.
https://www.google.com/search?q=%2F%...re+int+V+%3D+9
Silly typos in the code make it dead easy to search for.
There are numerous derived examples of some basic butchered code to choose from.
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