double large_cake_radius=0;//声明大蛋糕的面积？为什么必须要对这个变量进行初始化赋值才能运行？

Question

int main(){ int small_price=0;//声明一个小蛋糕的价格 int large_price=0;//声明大蛋糕的价格 double small_cake_radius;//声明小蛋糕的面积 double large_cake_radius=0;//声明大蛋糕的面积 double small_areaprice;//声明小蛋糕每平方英寸的价格 double large_areaprice;//声明大蛋糕每平方英寸的价格 cout << "请输入小蛋糕的价格\n"; cin >> small_price; cout << "请输入大蛋糕的价格\n"; cin >> large_price; cout << "请输入小蛋糕的半径\n"; cin >> small_cake_radius; cout << "请输入大蛋糕的半径\n"; cin >> large_price; small_areaprice = Buyarea(small_price,small_cake_radius); large_areaprice = Buyarea(large_price,large_cake_radius); if (small_areaprice > large_areaprice) { cout << "购买大蛋糕更加实惠"; } else cout << "购买小蛋糕更加优惠些"; system("pause"); return 0;}double Buyarea(int price,double radius){ const double PI = 3.14159; double aver_price; aver_price = PI* radius *radius/ price; return aver_price;}