Problème d`entraînement

u f
f f f
f
abba cababcbbbaaaab
u k f
n i f 1≤i≤n)j u
1≤j≤k)
n k
m
f g
abab
f n
πa,b(f)f a
b πa,c(cababcbbbaaaab) = caacaaaa A
k πa,b(f)k(k−1)
2{a, b}A
f πa,b(f)
f
uu
f
abbbaa
ba = 6
ukk u
apbqar
ab ,apbqar aba ,(ab)p ab ?

f, g a, b
δa,b a=b
fa
gb=f gb+δa,bf g
f
gn
m f g
n m
f g u
f g
f[i]i f fif
i f =abbbabba f[5] = a f5=abbba n
f m g
λ(f, g)f g
a b
λ(fa, gb)λ(f, gb), λ(fa, g)λ(f, g)
figji n f j
m g
0≤i≤n, 0≤j≤m
f=abbabbba g =aaabbab
min(n, m)