|
1 |
| -function Dijkstra(start, end){ |
2 |
| - tracer._sleep(333) |
3 |
| - var minIndex, minDistance; |
4 |
| - var S = []; // S[i] returns the distance from node v to node start |
5 |
| - var D = []; // D[i] indicates whether the i-th node is discovered or not |
6 |
| - for (var i = 0; i < G.length; i++){ |
7 |
| - D.push(false); |
8 |
| - S[i] = 19990719 // Some big distance (infinity) |
9 |
| - } |
10 |
| - S[start] = 0; // Starting node is at distance 0 from itself |
11 |
| - for(var k = 0; k < G.length; k++){ |
12 |
| - // Finding a node with the shortest distance from S[minIndex] |
13 |
| - minDistance = 19990719 // Some big distance (infinity) |
14 |
| - for(i = 0; i < G.length; i++){ |
15 |
| - if(S[i] < minDistance && !D[i]){ |
16 |
| - minDistance = S[i]; |
17 |
| - minIndex = i; |
18 |
| - } |
19 |
| - } |
20 |
| - tracer._visit(minIndex,undefined); |
21 |
| - tracer._sleep(500); |
22 |
| - D[minIndex] = true; |
23 |
| - if(minDistance == 19990719){ // If the distance is big (infinity), there is no more paths |
24 |
| - tracer._print('there is no path from ' + s + ' to ' + e); |
25 |
| - return false; |
26 |
| - } |
27 |
| - // For every unvisited neighbour of current node, we check |
28 |
| - // whether the path to it is shorter if going over the current node |
29 |
| - for(i = 0; i < G.length; i++){ |
30 |
| - if (G[minIndex][i] && !D[i] && ( S[i] > S[minIndex] + G[minIndex][i])){ |
31 |
| - S[i] = S[minIndex] + G[minIndex][i]; |
32 |
| - tracer._visit(i,minIndex,S[i]); |
33 |
| - tracer._sleep(500); |
34 |
| - tracer._leave(i,minIndex,S[i]); |
35 |
| - } |
36 |
| - } |
37 |
| - tracer._leave(minIndex,undefined); |
38 |
| - } |
39 |
| - tracer._print('the shortest path from ' + s + ' to ' + e + ' is ' + S[e]); |
| 1 | +function Dijkstra(start, end) { |
| 2 | + tracer._sleep(333); |
| 3 | + var MAX_VALUE = Infinity; |
| 4 | + var minIndex, minDistance; |
| 5 | + var S = []; // S[i] returns the distance from node v to node start |
| 6 | + var D = []; // D[i] indicates whether the i-th node is discovered or not |
| 7 | + for (var i = 0; i < G.length; i++) { |
| 8 | + D.push(false); |
| 9 | + S[i] = MAX_VALUE; |
| 10 | + } |
| 11 | + S[start] = 0; // Starting node is at distance 0 from itself |
| 12 | + for (var k = 0; k < G.length; k++) { |
| 13 | + // Finding a node with the shortest distance from S[minIndex] |
| 14 | + minDistance = MAX_VALUE; |
| 15 | + for (i = 0; i < G.length; i++) { |
| 16 | + if (S[i] < minDistance && !D[i]) { |
| 17 | + minDistance = S[i]; |
| 18 | + minIndex = i; |
| 19 | + } |
| 20 | + } |
| 21 | + tracer._visit(minIndex, undefined); |
| 22 | + tracer._sleep(500); |
| 23 | + D[minIndex] = true; |
| 24 | + if (minDistance == MAX_VALUE) { // If the distance is infinity, there is no more paths |
| 25 | + tracer._print('there is no path from ' + s + ' to ' + e); |
| 26 | + return false; |
| 27 | + } |
| 28 | + // For every unvisited neighbour of current node, we check |
| 29 | + // whether the path to it is shorter if going over the current node |
| 30 | + for (i = 0; i < G.length; i++) { |
| 31 | + if (G[minIndex][i] && !D[i] && ( S[i] > S[minIndex] + G[minIndex][i])) { |
| 32 | + S[i] = S[minIndex] + G[minIndex][i]; |
| 33 | + tracer._visit(i, minIndex, S[i]); |
| 34 | + tracer._sleep(500); |
| 35 | + tracer._leave(i, minIndex, S[i]); |
| 36 | + } |
| 37 | + } |
| 38 | + tracer._leave(minIndex, undefined); |
| 39 | + } |
| 40 | + tracer._print('the shortest path from ' + s + ' to ' + e + ' is ' + S[e]); |
40 | 41 | }
|
41 | 42 |
|
42 | 43 | var s = Math.random() * G.length | 0; // s = start node
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