方法1:
# include<stdio.h>
int main()
{
int n;
scanf("%d",&n);
int i;
double sum = 0.0;
int sign = 1;
for(i = 1; i<=n; i++){
sum += sign*1.0/i;
sign = -sign;
}
printf("f(%d)=%f\n",n,sum);
return 0;
}
方法2:
# include<stdio.h>
int main()
{
int n;
scanf("%d",&n);
int i;
double sum = 0.0;
double sign = 1.0;
for(i = 1; i<=n; i++){
sum += sign/i;
sign = -sign;
}
printf("f(%d)=%f\n",n,sum);
return 0;
}