SGU - 123
Description Here is your second problem, keep calm and solve it . Nacci sequence of numbers is known to all : F1 = 1; F2 = 1; Fn+1 = Fn + Fn-1, for n>1. You Input First line contains natural number K (0<K<41). Output First line should contain number S. Sample Input 5 Sample Output 12 Source |
简单数学求和题,,居然int都不会爆,,刚开始我还以为要long long。。
AC代码:
#include <cstdio> #include <cstring> #include <algorithm> #include <cmath> #define LL long long using namespace std; int a[42] = {0,1,1}; int main() { int k; for(int i=3; i<41; i++) { a[i] = a[i-1] + a[i-2]; } scanf("%d", &k); int ans = 0; for(int i=1; i<=k; i++) { ans += a[i]; } printf("%d\n", ans); return 0; }
时间: 2024-10-05 19:52:37