Merge pull request neetcode-gh#635 from Rixant/743-network-delay-time

Ahmad-A0 · web-flow · commit 53d48ed40749 · 2022-07-26T10:03:50.000+01:00
java: Created network delay time
diff --git a/java/743-Network-Delay-Time.java b/java/743-Network-Delay-Time.java
@@ -0,0 +1,50 @@
+// Bellman Ford ALgorithm
+// Time Complexty (n * t) | Space Complexity O(n) where t is the length of times
+class Solution {
+    public int networkDelayTime(int[][] times, int n, int k) {
+        
+        // initialize an array with max value of size n
+        int[] paths = new int[n];
+        Arrays.fill(paths, Integer.MAX_VALUE);
+        
+        paths[k - 1] = 0;
+        
+        for (int i = 0; i < n; i++){
+            
+            // make a copy of paths
+            int[] temp = new int[n];
+            temp = Arrays.copyOf(paths, paths.length);
+
+                // loop through times
+                for(int j = 0; j < times.length; j ++){
+                    
+                    int src = times[j][0]; // source
+                    int tgt = times[j][1]; // target
+                    int time = times[j][2]; // time
+                    
+                    if (temp[src - 1] != Integer.MAX_VALUE && temp[src - 1] + time < temp[tgt - 1]){
+                        temp[tgt - 1] = temp[src - 1] + time;
+                    }
+      
+                }
+            
+            // set paths to temp
+            paths = temp; 
+
+        }  
+        
+        int result= Integer.MIN_VALUE;
+        
+        // calculate max value
+        for(int i = 0; i < n;i++){
+            if(paths[i] == Integer.MAX_VALUE) {
+                return -1;
+            }
+            result = Math.max(result, paths[i]);
+        }
+       
+        // return result
+        return result;
+        
+    }
+}
