# include<stdio.h> int main(void) { int val; int f1 = 1; int f2 = 1; int f3 = 0; int sum =2;//sum变量用来存储斐波那契数列的和 printf("请您输入斐波那契数列的某项:"); scanf("%d",&val); if(val == 1) { f3 = 1; sum = 1; } else if(val == 2) { f3 = 2; sum = 3; } else { for(int i =3;i<=val;i++) { f3 = f1 + f2; f1 = f2; f2 = f3; sum += f3;//求前val项的和 } } printf("斐波那契数列第%d项的值为%d\n",val,f3); printf("前%d项的和为%d\n",val,sum); return 0; }
