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Difficulty: Easy · Topics: Discrete Mathematics, Functions, Function Combinatorics
Hech bir kirish qiymati joyida qolmaydi
Let X=\1, 2, 3, 4\. How many functions f:X→ X satisfy f(x)≠ x for every x?
X=\1, 2, 3, 4\ bo‘lsin. Nechta f:X→ X funksiya har bir x uchun f(x)≠ x ni qanoatlantiradi?