TLE in testcases 2 & 3 in Color The graph Problem on HackerEarth

#1

When the value of vertices is 1000000 and edges is 2000000, my code gives TLE.
How can this be rectified?

#2

you can start coloring from node 1 and see if there is a odd length cycle in the graph , then print No else keep printing it, it can be done in 1 dfs only , time complexity is O(n) ,
try it again , for the solution , let me know again