编程计算下面表达式前20项的和：1/(1*2)+1/(2*3)+1/(3*4)+⋯+1/(n*(n+1)) 输入格式：无 输出格式："s=%.3f\n"

#include <stdio.h>

int main() {
    double sum = 0;
    for (int i = 1; i <= 20; i++) {
        sum += 1.0 / (i * (i + 1));
    }
    printf("s=%.3f\n", sum);
    return 0;
}