c语言分子编写程序,输入一个正整数n,计算1-2/3+3/5-4/7+5/9-6/11+.的前n项之和.

int main(int argc,char *argv[]){int num_n = 1;int i = 0;double result = 0。0;printf("please input a Integer:");//scanf("%d",&num_n);num_n = 3;for(i=0; i