Question

用C语言编写程序求序列 2/1+3/2+5/3+8/5…前20项和，并输出。

Answer 1

#include <stdio.h>
main()
{
int a=1,b=2,t,i;
float sum=0;

for(i=1;i<=20;i++;)
{
sum=sum+(float)b/a;
t=a+b;
a=b;
b=t;
}
printf("%d",sum);
}

Answer 2

#include "stdio.h"
#include "string.h"

int main(){
int i;
double a = 2.0, b = 1.0, temp;
double sum = a/b;
for(i = 1; i <= 19; ++i){
temp = a;
a = a+b;
b = temp;
sum += a/b;
}
printf("%lf", sum);

}