Create: 787-Cheapest-Flights-Within-K-Stops.ts

typescript/787-Cheapest-Flights-Within-K-Stops.ts

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+function findCheapestPrice(n: number, flights: number[][], src: number, dst: number, k: number): number {
+    const adjacencyList = new Map();
+
+    for (let [start, end, cost] of flights) {
+        if (adjacencyList.has(start)) {
+            adjacencyList.get(start).push([end, cost]);
+        } 
+        else {
+            adjacencyList.set(start, [[end, cost]]);
+        }
+    }
+
+    const queue = [[0, src, k+1]];
+    const visited = new Map();
+
+    while (queue.length) {
+        queue.sort((a, b) => a[0] - b[0]);
+
+        const [cost, city, stops] = queue.shift();
+        visited.set(city, stops);
+
+        if (city === dst) {
+            return cost;
+        }
+
+        if (stops <= 0 || !adjacencyList.has(city)) {
+            continue;
+        }
+
+        for (let [nextCity, nextCost] of adjacencyList.get(city)) {
+            if (visited.has(nextCity) && visited.get(nextCity) >= stops-1) {
+                continue;
+            }
+
+            queue.push([cost+nextCost, nextCity, stops-1]);
+        }
+    }
+
+    return -1; 
+};