yanghui专题

poj 3021 A Number from Yanghui Triangle

推出公式来就是水题。 S(n,k) = C(n,0)+10^k*C(n,1)+10^2k*C(n,2)+.... ...+10^nk*C(n,n) 10^k*S(n,k) = 10^k*C(n,0)+10^2k*C(n,1)+10^3k*C(n,2)+.... ...+10^(n+1)k*C(n,n) 两式求和可得 S(n, k) + 10^k*S(n, k) = S(n+1, k)