R2__D2's blog

By R2__D2, history, 8 years ago, In English

Given N nodes and M edges. I have to color(only 2 colors) the nodes in such a way that at least one of the connected nodes of each nodes belong to different color. What will be the maximum number of nodes of same colored ? I am not sure about the range of N,M. I was working on bipartite graph. Suddenly I noticed it but failed to manage any idea to solve it.

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8 years ago, # |
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You can run dfs at each component, then select the type of color with larger amount of node covered and add it to the answer. (If there exists a component which is not bipartite, return error.)

Edit: Oh.. I misinterpreted the constraints, hold on. Gotta rethink it a bit more.

Edit2: I am raising my white flag, I don't know and would like to know a decent solution for this problem. The corner cases just kills the greedy approach and the graph nature and the situation makes dp and point compression much more complicated.

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    8 years ago, # ^ |
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    But How do I fix the color whenever I have a option to keep it same color as it's parent node?