#include <stdio.h>

#include <stdlib.h>

#include <math.h>

float polynomial(int n){

float sum=0;

int i;

for(i=1;i<=n;i++){

if(i%2 == 1)

sum += 1.0/i;

if(i%2 == 0)

sum -= 1.0/i;

}

return sum;

}

int main(int argc,char *argv[]) {

int t;

float sum;

scanf("%d",&t);

sum = polynomial(t);

printf("%f",sum);

return EXIT_SUCCESS;

}

#include<stdio.h>

int main()

{

int n;

double sum=0;//記錄總和初始值為0

printf("輸入n的值：");

scanf("%d",&n);

for(int i=1;i<=n;i++)sum+=1.0/i;

printf("前n項之和為：%lf\n",sum);

return 0;

}

執行透過,可用.