+NP-hard problems form a class in [Complexity Theory](/wiki/Complexity_Theory), representing tasks at least as difficult as any problem in [NP](/wiki/NP). For these, no efficient general algorithms are known, meaning solution time often grows dramatically with input size.
+## See also
+- [NP Complete](/wiki/NP_Complete)
+- [P vs NP](/wiki/P_vs_NP)
+- [Algorithm](/wiki/Algorithm)
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