Merge pull request #2375 from ys3593/main

Create 1514-path-with-maximum-probability.java

Author: a93a

java/1514-path-with-maximum-probability.java

@@ -0,0 +1,74 @@
+class Solution {
+    public double maxProbability(int n, int[][] edges, double[] succProb, int start, int end) {
+        // create the graph
+        List<double[]>[] graph = new LinkedList[n];
+        for (int i = 0; i < n; i++) {
+            graph[i] = new LinkedList<>();
+        }
+        
+        for (int i = 0; i < edges.length; i++) {
+            double from =  edges[i][0];
+            double to =  edges[i][1];
+            double weight = succProb[i];
+            double[] m = new double[2];
+            m[0] = to;
+            m[1] = weight;
+            graph[edges[i][0]].add(m);
+            double[] k = new double[2];
+            k[0] = from;
+            k[1] = weight;
+            graph[edges[i][1]].add(k);
+        }
+        
+        // call dijkstra and return 
+        return dijkstra(start, end, graph);
+    }
+    
+    class State{
+        int id;
+        double proToStart;
+        
+        public State(int id, double proToStart){
+            this.id = id;
+            this.proToStart = proToStart;
+        }
+    }
+    
+    private double dijkstra(int start, int end, List<double[]>[] graph){
+        double[] proTo = new double[graph.length];
+        // 初始化为一个去不到的值
+        Arrays.fill(proTo, -1);
+        proTo[start] = 1;
+        
+        PriorityQueue<State> pq = new PriorityQueue<State>((a, b) -> {
+        return Double.compare(b.proToStart, a.proToStart);
+    });
+        pq.offer(new State(start, 1));
+        
+        while (!pq.isEmpty()){
+            State cur = pq.poll();
+            int curid = cur.id;
+            double curproToStart = cur.proToStart;
+            
+            if (curid == end) {
+                return curproToStart;
+            }
+            
+            if (proTo[curid] > curproToStart) {
+                continue;
+            }
+            
+            List<double[]> nexts = graph[curid];
+            for (double[] next: nexts) {
+                double proToNext = proTo[curid] * next[1];
+                int idx = (int) next[0];
+                if (proToNext > proTo[idx]) {
+                    proTo[idx] = proToNext;
+                    pq.offer(new State(idx, proToNext));
+                }
+            }
+        }
+        
+        return 0;
+    }
+}