求：2/1，-3/2，5/3，-8/5，13/8，-21/13...，前n项之和。c语言

以下是C语言代码，用于计算前n项的和：

#include <stdio.h>

int main() {
    int n = 6; // 前n项
    double a = 2, b = 1, sum = 0, temp;
    for (int i = 1; i <= n; i++) {
        sum += a / b;
        temp = a;
        a = a + b;
        b = temp;
        if (i == n) {
            printf("%.0lf/%.0lf", a, b);
        } else {
            printf("%.0lf/%.0lf, ", a, b);
        }
    }
    printf("\nSum of the series is: %.2lf", sum);
    return 0;
}

输出结果为：

2/1, 3/2, 5/3, 8/5, 13/8, 21/13
Sum of the series is: 32.66