c++ - c++求和使用for循环和二维数组

Question

我正在尝试创建一个循环来计算每年的图书总销售额。我还需要计算过去三年的图书总销售额。

我已经计算出如何计算所有 3 年的总和，但是，我在计算每年售出的总图书订单时遇到了麻烦。这是我到目前为止所拥有的。

    const int months = 12;
    const int years =3;
    string namonths [months] = {"January", "February", "March", "April",
                 "May", "June", "July", "August", "September",
                 "October", "November", "December"};
int bookorders[years][months];
int sum=0;

for (int i = 0; i < years ; i++) {
for (int n = 0; n < months; n++) {

    std::cout << "Year " << i + 1 << " Month " << namonths[n] <<":"<< std::endl;

    cin >> bookorders[i][n];

    sum += bookorders[i][n];
}

}

//  std::cout << "total orders are for each year are: " << sum <<std::endl;
std::cout << "total orders are " << sum <<std::endl;

Answer 1

1. 添加一个存储每年总和的新变量： int sumPerYear[years];
2. 在两个 for 语句之间： sumPerYear[i] = 0;
3. 然后在 for 循环核心中说： sumPerYear[i] += bookorders[i][n];
4. 最后在最后： for (int i = 0; i < years ; i++) std::cout << "year " << i << " sum: " << sumPerYear[i] << std::endl;

Answer 2

这里试试这个。sumperYear 是最初为零的变量。在外部 for 循环的每次迭代中，都会显示 sumperYear。

for (int i=0; i<years; i++) { for (int j=0 ; j< months; j++) { sumperYear+=bookOrders[i][j]; } cout<<"For the year:" << i+1 << " the total orders are: "<< sumperYear; sumperYear=0; }