题目

QQ图片20190331144301.png

代码

#include<stdio.h>
#include<stdlib.h>
//1+1/3+1/3*2/5+1/3*2/5*3/7...

// cnt/divident
//cnt++; divident += 2;
int main()
{
    int divident = 1;
    int cnt = 0;
    double t1=1,t2=1;
    double evenPi = 1;
    double evenPiPre = 0;
    double precision;
    printf("输入精度:");
    scanf_s("%lf", &precision);

    while (((2*evenPi) - (2*evenPiPre)) > precision)
    {
        evenPiPre = evenPi;
        t1 = t1*t2;
        cnt++;
        divident += 2;
        t2 = (double)cnt / divident;
        evenPi = evenPiPre + t1*t2;
        printf("%f=%f+%f*%f\n", evenPi, evenPiPre, t1,t2);
    }
    printf("PI = %7f\n", evenPi*2);
    system("pause");
    return 0;
}

结果

输出.PNG