在手机上用易历知食软件里面的微C程序设计功能来编个示例代码并运行程序,手机上代码如下:
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/cb8065380cd791239946f06aa6345982b2b7800d?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/ae51f3deb48f8c54a2eaa23131292df5e0fe7ff6?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
运行结果如下:
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/f3d3572c11dfa9ec47dd320969d0f703918fc139?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
完整文本代码:
#include <stdio.h>
double Sn( double a1,double an,double d);
int main()
{
double a1,an,d;
printf("输入第一项、最后一项和公差(空格相隔)\n");
scanf("%lf %lf %lf",&a1,&an,&d);
printf("等差数列的和是:%lf",Sn(a1,an,d));
return 0;
}
double Sn( double a1,double an,double d){
double n = (an - a1) / d + 1;
double sn = (a1 + an)*n/2.0;
return sn;
}