为什么openaccount(&account); deposit(&account, 20); withdraw(&account, 19.89)中的account前面要加& #include <stdio.h> typedef struct { double balance; } bankaccount; //开户 void openaccount(bankaccount *account) { account->balance = 0; printf("开户成功"); } void deposit(bankaccount *account, double amount) { account->balance += amount; printf("存款 %.2f 成功", amount); } void withdraw(bankaccount *account, double amount) { if (account->balance >= amount) { account->balance -= amount; printf("取款 %.2f 成功", amount);