求sum=2/1+3/2+5/3+....

 1 #include<stdio.h>
 2 int main()
 3 {
 4     float sum,i,j,z;  //整数的除法运算只取整
 5     sum = 0.0;
 6     z = 0.0;
 7     int k = 1;
 8     for (i = 2.0, j = 1.0; k <= 10;k++)
 9     {
10         sum += i / j;
11         z = i;
12         i = i + j;
13         j = z;
14     }
15     printf("sum = %f", sum);
16 
17 
18     return 0;
19 }