fix: remove NP-hard claim

README.md

@@ -21,7 +21,7 @@ $`A_{ij} \in \{-1, 0, 1\} | i \in [0, N) \cap j \in [0, M)`$ and $N$ is the numb
 This formulation is based on the fact that the true phase differences, $2\pi k + x$, should fulfill the irrotationality constraint, which means the summation of phase derivatives of each elementary cycles is zero.
 This is the general form of the network programming approach proposed in the paper "[A novel phase unwrapping method based on network programming](https://ieeexplore.ieee.org/document/673674)".
 
-Unwrapping phase with Kamui can be computationally heavy due to the fact that ILP is NP-hard.
+Unwrapping phase with Kamui can be computationally heavy.
 Acceleration techniques, such as dividing the graph into subgraphs, will be implemented in the future.
 
 ## Installation
@@ -141,4 +141,4 @@ def unwrap_arbitrary(
 - [A novel phase unwrapping method based on network programming](https://ieeexplore.ieee.org/document/673674)
 - [Phase Unwrapping via Graph Cuts](https://ieeexplore.ieee.org/document/4099386)
 - [Edgelist phase unwrapping algorithm for time series InSAR analysis](https://opg.optica.org/josaa/abstract.cfm?uri=josaa-27-3-605)
-- [Time Series Phase Unwrapping Based on Graph Theory and Compressed Sensing](https://ieeexplore.ieee.org/document/9387451?arnumber=9387451)
+- [Time Series Phase Unwrapping Based on Graph Theory and Compressed Sensing](https://ieeexplore.ieee.org/document/9387451?arnumber=9387451)