C++酒店营收程序循环异常：二次循环未正确累加楼层数据

问题描述 #

我写了一个计算酒店营收的C++程序，里面有两个for (int a = 1; a <= floor; a++)循环。第一个循环能正常读取楼层数（比如输入2时会依次处理1、2层的房间数据），但第二个循环计算总营收、总房间数等统计数据时，没法累加各楼层的数据，只保留最后一层（第二层）的结果。

举个例子：输入floor=2，第一层参数是20间房（10间single、2间double、1间king、1间suite），第二层参数是10间房（5间single、1间double，king和suite为0），预期总营收1375美元、总房间30间、已入住20间，但实际输出是营收375美元、总房间10间、已入住6间。

原代码 #

#include <iostream>
#include <string>
#include <iomanip>
using namespace std;

int main()
{
    string location;
    const int minFloor = 1, maxFloor = 5, minRoom = 1, maxRoom = 30;
    int floor, room, singleRoom, doubleRoom, kingRoom, suiteRoom;
    int singleRate = 60, doubleRate = 75, kingRate = 100, suiteRate = 150;
    double income, occupancyRate, total_of_rooms, occupiedRoom, unoccupiedRoom;



    cout << "\nEnter the total number of floors in the hotel: ";
    cin >> floor; // not more than 5

    while (floor < minFloor || floor > maxFloor)
    {
        cout << "\nTne number of floors should be between 1 and 5 !! Please try again." << endl;
        cout << "\nEnter the total number of floors in the hotel: ";
        cin >> floor;
    }


    for (int a = 1; a <= floor; a++)
    {
        cout << "\nEnter total number of rooms in the " << a << "th Floor: ";
        cin >> room; //not more than 30

        while (room < minRoom || room > maxRoom)
        {
            cout << "\nThe number of rooms should be between 1 and 30 !! Please try again." << endl;
            cout << "\nEnter total number of room in the " << a << "th Floor: ";
            cin >> room;
        }

        cout << "\nHow many SINGLE rooms are occupied on the " << a << "th Floor: ";
        cin >> singleRoom;

        cout << "How many DOUBLE rooms are occupied on the " << a << "th Floor: ";
        cin >> doubleRoom;

        cout << "How many KING rooms are occupied on the " << a << "th Floor: ";
        cin >> kingRoom;

        cout << "How many SUITE rooms are occupied on the " << a << "th Floor: ";
        cin >> suiteRoom;

        int totalRoom = singleRoom + doubleRoom + kingRoom + suiteRoom;
        
        while (totalRoom > room) //checking the sum
        {
            cout << "\nThe total number of occupied rooms exceeds the total number of rooms on this floor. Please try again !!";
            
            cout << "\nHow many SINGLE rooms are occupied on the " << a << "th Floor: ";
            cin >> singleRoom;

            cout << "How many DOUBLE rooms are occupied on the " << a << "th Floor: ";
            cin >> doubleRoom;

            cout << "How many KING rooms are occupied on the " << a << "th Floor: ";
            cin >> kingRoom;

            cout << "How many SUITE rooms are occupied on the " << a << "th Floor: ";
            cin >> suiteRoom;

            int totalRoom = singleRoom + doubleRoom + kingRoom + suiteRoom;

            if (totalRoom < room)
                break; //break cause otherwise this thing won't stop
        }


    }


   for (int a = 1; a <= floor; a++) //for some reason it doesn't read the floor variable
    {
        income = (singleRoom * singleRate) + (doubleRoom * doubleRate) + (kingRoom * kingRate) + (suiteRoom * suiteRate);
        
        total_of_rooms = room;

        occupiedRoom = singleRoom + doubleRoom + kingRoom + suiteRoom;

    }
    
    cout << "Hotel Income: " << "$" << income << endl
    << "Total # of rooms: " << total_of_rooms << endl

    << "Total # of Occupied Rooms: " << occupiedRoom << endl

}

问题原因 #

1. 统计变量未初始化且未累加：income、total_of_rooms、occupiedRoom这些统计变量没有初始化为0，而且第二个循环里是直接赋值（比如income = ...），不是累加（income += ...），每次循环都会把之前的数值覆盖，最后只保留最后一次循环的结果。
2. 楼层数据未持久化：第一个循环里的room、singleRoom等变量是全局的，每处理完一层，这些变量就会被下一层的数据覆盖，第二个循环根本拿不到之前楼层的数据，只能读取最后一层的数值。
3. 第二个循环完全冗余：不需要单独开一个循环来统计，直接在第一个循环处理每层数据的时候，同步完成累加统计就可以了。

修复后的代码 #

#include <iostream>
#include <string>
#include <iomanip>
using namespace std;

int main()
{
    string location;
    const int minFloor = 1, maxFloor = 5, minRoom = 1, maxRoom = 30;
    int floor, room, singleRoom, doubleRoom, kingRoom, suiteRoom;
    int singleRate = 60, doubleRate = 75, kingRate = 100, suiteRate = 150;
    // 初始化统计变量为0
    double income = 0, occupancyRate, total_of_rooms = 0, occupiedRoom = 0, unoccupiedRoom;

    cout << "\nEnter the total number of floors in the hotel: ";
    cin >> floor; 

    while (floor < minFloor || floor > maxFloor)
    {
        cout << "\nThe number of floors should be between 1 and 5 !! Please try again." << endl;
        cout << "\nEnter the total number of floors in the hotel: ";
        cin >> floor;
    }

    for (int a = 1; a <= floor; a++)
    {
        cout << "\nEnter total number of rooms in the " << a << "th Floor: ";
        cin >> room; 

        while (room < minRoom || room > maxRoom)
        {
            cout << "\nThe number of rooms should be between 1 and 30 !! Please try again." << endl;
            cout << "\nEnter total number of room in the " << a << "th Floor: ";
            cin >> room;
        }

        cout << "\nHow many SINGLE rooms are occupied on the " << a << "th Floor: ";
        cin >> singleRoom;

        cout << "How many DOUBLE rooms are occupied on the " << a << "th Floor: ";
        cin >> doubleRoom;

        cout << "How many KING rooms are occupied on the " << a << "th Floor: ";
        cin >> kingRoom;

        cout << "How many SUITE rooms are occupied on the " << a << "th Floor: ";
        cin >> suiteRoom;

        int totalRoom = singleRoom + doubleRoom + kingRoom + suiteRoom;
        
        while (totalRoom > room) 
        {
            cout << "\nThe total number of occupied rooms exceeds the total number of rooms on this floor. Please try again !!";
            
            cout << "\nHow many SINGLE rooms are occupied on the " << a << "th Floor: ";
            cin >> singleRoom;

            cout << "How many DOUBLE rooms are occupied on the " << a << "th Floor: ";
            cin >> doubleRoom;

            cout << "How many KING rooms are occupied on the " << a << "th Floor: ";
            cin >> kingRoom;

            cout << "How many SUITE rooms are occupied on the " << a << "th Floor: ";
            cin >> suiteRoom;

            totalRoom = singleRoom + doubleRoom + kingRoom + suiteRoom;

            if (totalRoom <= room)
                break;
        }

        // 在第一个循环里直接累加统计数据
        income += (singleRoom * singleRate) + (doubleRoom * doubleRate) + (kingRoom * kingRate) + (suiteRoom * suiteRate);
        total_of_rooms += room;
        occupiedRoom += singleRoom + doubleRoom + kingRoom + suiteRoom;
    }

    // 计算空置房间数和入住率（可选补充）
    unoccupiedRoom = total_of_rooms - occupiedRoom;
    occupancyRate = (occupiedRoom / total_of_rooms) * 100;

    cout << fixed << setprecision(2);
    cout << "\nHotel Income: $" << income << endl
         << "Total # of rooms: " << total_of_rooms << endl
         << "Total # of Occupied Rooms: " << occupiedRoom << endl
         << "Total # of Unoccupied Rooms: " << unoccupiedRoom << endl
         << "Occupancy Rate: " << occupancyRate << "%" << endl;

    return 0;
}

修复说明 #

• 初始化所有统计变量为0，避免未定义行为。
• 删除冗余的第二个循环，在处理每层数据的第一个循环里直接完成累加操作（使用+=替代=）。
• 修复了原代码中拼写错误（Tne改为The）和循环内重复定义totalRoom的问题。
• 补充了空置房间数和入住率的计算，让输出更完整。
• 添加了fixed和setprecision(2)保证金额和百分比的输出格式更规范。

内容的提问来源于stack exchange，提问作者Michelle