有一分数序列： 2/1 3/2 5/3 8/5 13/8 21/13… 求出这个数列的前N项之和，保留两位小数。
#include<stdio.h> int main() { double num,fz=2,t,fm=1,sum=0; scanf("%lf",&num); while(num){ sum += fz/fm; t = fm; fm = fz; fz += t; num--; } printf("%.2lf",sum); return 0; }
#include<stdio.h> int main() { double num,fz=2,t,fm=1,sum=0; scanf("%lf",&num); while(num){ sum += fz/fm; t = fm; fm = fz; fz += t; num--; } printf("%.2lf",sum); return 0; }
