C语言求助求助求助

// 求x所有因子之和 int fun1(int x){ int i, sum = 0; for(i = 2; i <= x/2; ++i) if(x%i == 0) sum += i; return sum;}// 求分数序列之和float fun2(int n){ float a = 2.0f, b = 1.0f, sum = 0; do{