Update and rename ShortestAlternatingPath.cpp to medium-1129-shortest_path_alternating_colors.cpp

Author: matthewgoembel

Codes/ShortestAlternatingPath.cpp renamed to Codes/medium-1129-shortest_path_alternating_colors.cpp

@@ -1,4 +1,28 @@
-//implemented using Bellman's ford algo
+// You are given an integer n, the number of nodes in a directed graph where the nodes are labeled from 0 to n - 1.
+// Each edge is red or blue in this graph, and there could be self-edges and parallel edges.
+
+// You are given two arrays redEdges and blueEdges where:
+
+// redEdges[i] = [ai, bi] indicates that there is a directed red edge from node ai to node bi in the graph, and
+// blueEdges[j] = [uj, vj] indicates that there is a directed blue edge from node uj to node vj in the graph.
+
+// Return an array answer of length n, where each answer[x] is the length of the shortest path from node 0 to node x such that 
+// the edge colors alternate along the path, or -1 if such a path does not exist.
+
+ 
+
+// Example 1:
+
+// Input: n = 3, redEdges = [[0,1],[1,2]], blueEdges = []
+// Output: [0,1,-1]
+
+// Example 2:
+
+// Input: n = 3, redEdges = [[0,1]], blueEdges = [[2,1]]
+// Output: [0,1,-1]
+
+
+// implemented using Bellman's ford algo
 class Solution {
 public:
     vector<int> shortestAlternatingPaths(int n, vector<vector<int>>& redEdges, vector<vector<int>>& blueEdges) {