C 语言查找等比数列和的程序

编写一个 C 语言程序，使用数学公式和不使用数学公式查找等比数列（G.P. Series）的和。

等比数列

等比数列是指一个序列，其中下一个元素是通过将公比乘以前一个元素得到的。或者说，等比数列是这样一种数字序列，其中任何连续数字（项）的公比始终相同。

等比数列和背后的数学公式
Sn = a(rⁿ) / (1- r)
Tn = ar^(n-1)

C 语言查找等比数列和的程序示例

该程序允许用户输入首项、项数和公比。然后，它将找到等比数列的和。这里，我们使用了 For 循环 来显示 G.P. 数列，这是可选的。

/* Program to find Sum of Geometric Progression Series */
#include <stdio.h>
#include<math.h>
int main() {
    
    int a, n, r;
    float tn, sum = 0;
    
    printf(" Please Enter First Number of an G.P Series:  ");
    scanf("%d", &a);
    printf(" Please Enter the Total Numbers in this G.P Series:  ");
    scanf("%d", &n);
    printf(" Please Enter the Common Ratio:  ");
    scanf("%d", &r);
    
    sum = (a * (1 - pow(r, n ))) / (1- r);
    tn = a * (pow(r, n - 1));
    
    printf("\n The Sum of Geometric Progression Series =  %.2f", sum);
    printf("\n The tn Term of Geometric Progression Series = %.2f \n", tn);
    return 0;
}

 Please Enter First Number of an G.P Series:  1
 Please Enter the Total Numbers in this G.P Series:  5
 Please Enter the Common Ratio:  2

 The Sum of Geometric Progression Series =  31.00
 The tn Term of Geometric Progression Series = 16.00 

在此 程序 中，我们没有使用任何数学公式。

/* Program to find Sum of Geometric Progression Series */
#include <stdio.h>
#include<math.h>
int main() {
    
    int a, n, r, value, i;
    float sum = 0;
    
    printf(" Please Enter First Number of an G.P Series:  ");
    scanf("%d", &a);
    printf(" Please Enter the Total Numbers in this G.P Series:  ");
    scanf("%d", &n);
    printf(" Please Enter the Common Ratio:  ");
    scanf("%d", &r);
    
    value = a;
    printf("G.P Series  :  ");
    for(i = 0; i < n; i++)
    {
        printf("%d  ", value);
        sum = sum + value;
        value = value * r;
    }
    printf("\n The Sum of Geometric Progression Series =  %f\n", sum);
    return 0;
}

 Please Enter First Number of an G.P Series:  2
 Please Enter the Total Numbers in this G.P Series:  5
 Please Enter the Common Ratio:  2
G.P Series  :  2  4  8  16  32  
 The Sum of Geometric Progression Series =  62.000000

C 语言使用函数计算等比数列和的程序

这个等比数列 C 程序 与上面的相同。但是，我们使用 函数 将 C 编程 逻辑分开了。

/* Program to find Sum of Geometric Progression Series */
#include <stdio.h>
#include<math.h>
int sumofGP(int a, int n, int r)
{
    int sum = (a * (1 - pow(r, n))) / (1- r);
    return sum;
}

int main() {
    
    int a, n, r;
    float sum = 0;
    
    printf(" Please Enter First Number of an G.P Series:  ");
    scanf("%d", &a);
    printf(" Please Enter the Total Numbers in this G.P Series:  ");
    scanf("%d", &n);
    printf(" Please Enter the Common Ratio:  ");
    scanf("%d", &r);
    
    sum = sumofGP(a, n, r);
    printf("\n The Sum of Geometric Progression Series =  %f\n", sum);
    return 0;
}