C语言编程：1-1⼀2阶乘+1⼀4的阶乘-1⼀6的阶乘+1⼀8的阶乘-........1⼀2n阶乘的前十项的得数

#include

int main()
{
double fac;
double sum;
int n;
int i;

sum=1.0;
n = 10;
fac = 1;

printf("sum = 1");
for( i=0; i fac = fac *(2*i+1)*(2*i+2);
if (i%2==0) {
sum -= 1/fac;
printf("-1/%d!", (2*i+2));
}
else {
sum += 1/fac;
printf("+1/%d!", (2*i+2));
}
}

printf("\n");
printf("= %lf\n", sum);
return 0;
}

sum = 0.540302