java: Create cheapest flights within K stops

Author: rixant

java/787-Cheapest-Flights-Within-K-Stops.java

@@ -0,0 +1,47 @@
+// Time Complexity O(k * n) | Space Complexity O(n)
+class Solution {
+    public int findCheapestPrice(int n, int[][] flights, int src, int dst, int k) {
+        
+        // initialize an array with max value of size n
+        int[] prices = new int[n];
+        Arrays.fill(prices, Integer.MAX_VALUE);
+        
+        // price from source to source is always 0
+        prices[src] = 0;
+        
+        for (int i = 0; i <= k; i++){
+            
+            // make a copy of prices
+            int[] temp = new int[n];
+            temp = Arrays.copyOf(prices, prices.length);
+
+                // loop through flights
+                for(int j = 0; j < flights.length; j ++){
+                    
+                    int s = flights[j][0]; // from
+                    int d = flights[j][1]; // to
+                    int p = flights[j][2]; // price
+                    
+                    if (prices[s] == Integer.MAX_VALUE){
+                        continue;
+                    }
+                    
+                    if (prices[s] + p < temp[d]){
+                        temp[d] = prices[s] + p;
+                    }
+                    
+                }
+            
+            // set prices to temp
+            prices = temp; 
+        }
+        
+        
+        if (prices[dst] != Integer.MAX_VALUE){
+            return prices[dst];
+        }
+        
+        return -1;
+        
+    }
+}