摘要： 幸运数字的定义是这样：仅含4和7且不比n小的数为n的幸运数字。输入范围l，r要求输出这个范围内的数字的幸运数字之和。代码： 1 #include 2 #define N 1024 3 typedef long long ll; 4 ll a[N+1]; 5 ll f(ll n) 6 { 7 if(n==0) 8 return 0; 9 int i;10 ll ans=0;11 for(i=1;i<=N;i++)12 {13 if(a[i]<n)14 ans+=a[i]*(a[i]-a[i-1]);1... 阅读全文

摘要： Numbersk-bonacci (kis integer,k > 1) are a generalization of Fibonacci numbers and are determined as followsF(k, n) = 0, for integern,1 ≤ n k.Note that we determine thek-bonacci numbers,F(k, n), only for integer values ofnandk.You've got a numbers, represent it as a sum of several (at least t 阅读全文