A digraph is a graph in which each edge has an orientation. A linear directed path, , is a path whose all edges have the same orientation. A linear simple graph is called directed cordial if it admits 0 - 1 labeling that satisfies certain condition. In this paper, we study the cordiality of directed paths？？and their second power . Similar studies are done for ？and the join ？. We show that ,？ and ？are directed cordial. Sufficient conditions are given to the join？？ to be directed cordial.
References
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Gallian, J.A. (2017) A Dynamic Survey of Graph Labeling. The Electronic Journal of Combinatorics, Twentieth Edition, December 22, 1-432.
https://www.combinatorics.org/ojs/index.php/eljc/article/view/DS6/versions
[2]
Harary, F. (1972) Graph Theory. Addison-Wesley Reading Mass, Massachusetts.
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Diab, A.T. (2010) On Cordial Labeling of the Second Power of Paths with Other Graphs. ARS-Combinatoria, 97A, 327-343.
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Cahit, I. (1987) Cordial Graphs: A Weaker Version of Graceful and Harmonious Graphs. ARS-Combinatoria, 23, 201-207.
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Cahit, I. (1990) On Cordial and 3-Eqtitable Labeling of Graphs. Utilitas Mathematica, 37, 189-198.
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, is a path whose all edges have the same orientation. A linear simple graph is called directed cordial if it admits 0 - 1 labeling that satisfies certain condition. In this paper, we study the cordiality of directed paths？![\"\"](\"Edit_165dd9bd-2294-41a7-addc-e2ee2a3d8923.bmp\")
. Similar studies are done for ![\"\"](\"Edit_2699834e-3f0a-49f2-895f-94e38d731b34.bmp\")
？and the join ![\"\"](\"Edit_b2e4e1d2-1c5c-4637-b77a-32705b07a255.bmp\")
？. We show that 
