This software has been modified by 
Chi-Him Wong and Yiu-Cheong Tam, described in 
"Negative Cycle Detection Problem", ESA 2005: 652-663,

mgorc.c , mbfct.c and mbfcf.c has been added into ./src/

mgorc - The modified version of Goldberg - Radzik Algorithm
mbfct - The modified version of Bellman-Ford Algorithm with Tarjan strategy
mbfcf - The modified version of Bellman-Ford Algorithm with Walk to Root strategy

The detailed description can be found in the paper.

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