我做错了什么？我无法理解。如果有人有任何想法如何找出哪个Sea Trip有最大的销售量[门票总数最大]然后我如何显示它 - 你会注意到它应该在源代码中的位置。我一直在尝试和尝试，我就不能了..在过去的7-8小时内没有在笔记本电脑前移动。需要帮助。
#include<iostream>
#include<fstream>
#include<string>
#include<cstdlib>
using namespace std;
struct trip
{
int day; //day of Sea Trip
int fln; //No. of Sea Trip
char name[14]; //Ship name
char capname[14]; // Captain Name
char destination[14]; // Destination
int br1; // No. pass in 1 class
int br2; // No. pass in 2 class
float price1; // Ticket price 1 class
float price2; // Ticket price 2 class
float sum; // Sum of sold tickets
};
fstream seatrips;
int add_trip(trip trip[]) //adding sea trips
{
int n;
seatrips.open("SeaTrips.txt", ios::out);
if (seatrips.fail())
{
cout << "Opening file had no success";
exit(1);
}
cout << "Enter the number of Sea Trips (max 25): ";
do
{
cin >> n;
} while (n < 0 || n > 25);
for (int i = 0; i < n; i++)
{
cout << "Enter the day of the trip (1-31) : ";
do{
cin >> trip.day;
} while (trip.day < 1 || trip.day > 31);
seatrips << trip.day << endl;
cout << "Sea Trip Number : ";
cin >> trip.fln;
seatrips << trip.fln << endl;
cout << "Ship name : ";
cin >> trip.name;
seatrips << trip.name << endl;
cout << "Captain name : ";
cin >> trip.capname;
seatrips << trip.capname << endl;
cout << "Destination : ";
cin >> trip.destination;
seatrips << trip.destination << endl;
cout << "Number of passengers in 1. class : ";
cin >> trip.br1;
seatrips << trip.br1 << endl;
cout << "Number of passengers in 2.class : ";
cin >> trip.br2;
seatrips << trip.br2 << endl;
cout << "Ticket price 1. class : ";
do{
cin >> trip.price1;
seatrips << trip.price1 << endl;
} while (trip.price1 < 1);
cout << "Ticket price 2. class : ";
do{
cin >> trip.price2;
seatrips << trip.price2 << endl;
} while (trip.price2 < 1);
trip.sum = trip.br1 * trip.price1 + trip.br2 * trip.price2;
seatrips << trip.sum;
cout << endl << endl;
}
seatrips.close();
return n;
}
void edit(trip trip[], int n) //editing pass. info
int t_fln; //temp sea trip number
seatrips.open("SeaTrips.txt", ios::out);
seatrips.seekg(0);
if (seatrips.fail())
{
cout << "Unable to open SeaTrips file";
exit(1);
}
cout << "Enter the number of the sea trip u want to edit: ";
cin >> t_fln;
for (int i = 0; i < n; i++)
{
seatrips >> trip.day;
seatrips >> trip.fln;
seatrips >> trip.name;
seatrips >> trip.br1;
seatrips >> trip.br2;
seatrips >> trip.price1;
seatrips >> trip.price2;
seatrips >> trip.sum;
if (t_fln == trip.fln)
{
cout << "Add new number of ppl in 1. class : ";
cin >> trip.br1;
seatrips << trip.br1 << endl;
cout << "Add new number of ppl in 2. class : ";
cin >> trip.br2;
seatrips << trip.br2 << endl;
}
}
seatrips.close();
}
void look(trip trip[], int n) //search by ship name, and list of all trips
int choice2, flag = 0;
string t_name;
seatrips.open("SeaTrips.txt", ios::in);
seatrips.seekg(0);
if (seatrips.fail())
{
cout << "Unable to open";
exit(1);
}
do{
cout << endl << "Choose..." << endl;
cout << "1. Find a Sea Trip by entered Ship Name." << endl;
cout << "2. List of all Sea Trips" << endl;
cout << "3. Show Sea Trip with Maximum Sold Tickets" << endl;
cout << "4. Exit" << endl;
cout << "Choice: ";
cin >> choice2;
switch (choice2)
{
case 1:{cout << "Enter info about the wanted Sea Trip..." << endl;
cout << "Ship Name: ";
cin >> t_name;
for (int i = 0; i < n; i++)
{
seatrips >> trip.day;
seatrips >> trip.fln;
seatrips >> trip.name;
seatrips >> trip.capname;
seatrips >> trip.destination;
seatrips >> trip.br1;
seatrips >> trip.br2;
seatrips >> trip.price1;
seatrips >> trip.price2;
seatrips >> trip.sum;
if (t_name == trip.name)
{
cout << "Day: " << trip.day << endl;
cout << "Number of Sea Trip: " << trip.fln << endl;
cout << "Ship name : " << trip.name << endl;
cout << "Name of captain: " << trip.capname << endl;
cout<< "Destination: " << trip.destination << endl;
cout << "Number of passengers in 1. class: " << trip.br1 << endl;
cout << "Ticket price 1. class " << trip.price1 << endl;
cout << "Number of passengers in 2. class: " << trip.br2 << endl;
cout << "Ticket price 2. class " << trip.price2 << endl;
cout << "Sum of sold tickets: " << trip.sum << endl;
cout << endl;
flag++;
}
} break; }
case 2:
for (i = 0; i < n; i++)
{
seatrips >> trip.day;
seatrips >> trip.fln;
seatrips >> trip.name;
seatrips >> trip.capname;
seatrips >> trip.destination;
seatrips >> trip.br1;
seatrips >> trip.br2;
seatrips >> trip.price1;
seatrips >> trip.price2;
seatrips >> trip.sum;
cout << "Day: " << trip.day << endl;
cout << "Number of Sea Trip: " << trip.fln << endl;
cout << "Ship Name: " << trip.name << " Captain Name " << trip.capname << " Destination " << trip.destination << endl;
cout << "Number of ppl 1. class : " << trip.br1 << endl;
cout << "Ticket price 1. class: " << trip.price1 << endl;
cout << "Number of ppl 2. class: " << trip.br2 << endl;
cout << "Ticket price 2. class: " << trip.price2 << endl;
cout << "Sum of sold tickets: "<< trip.sum << endl; }
} break; }
case 3:
/* max sales function
*
* Trip's sum is the largest one
* And display the Sea Trip here.
*
*/
} while (choice2 != 4);
seatrips.close();
}
void main()
{
setlocale(LC_ALL, "Bulgarian");
int choice1;
int n;
trip trip[25];
do
{
cout << "Menu..." << endl;
cout << "1. Adding and saving to file Sea Trips data [deletes any existing]" << endl;
cout << "2. Editing content" << endl;
cout << "3. Search and look up" << endl;
cout << "4. End" << endl;
cout << "Enter your choice: ";
cin >> choice1;
switch (choice1)
{
case 1:n = add_trip(trip); break;
case 2: edit(trip, n); break;
case 3:look(trip, n);
}
} while (choice1 != 4);
}
答案 0 :(得分：0)
给定vector trip：
std::vector<trip> database;
你可以迭代通过它寻找最大的总和，并维持一个最大总和的旅程迭代器：
float largest_sum = -1.0f;
std::vector<trip>::const_iterator trip_with_largest_sum = database.end();
std::vector<trip>::const_iterator iter;
for (iter = database.begin(); iter != database.end(); ++iter)
{
if (iter->sum > largest_sum)
{
largest_sum = iter->sum;
trip_with_largest_sum = iter;
}
}
在循环结束时，trip_with_largest_sum将指向具有最大总和的行程或database.end()如果未找到任何项目。
如果你坚持使用数组，相同的算法，使用索引变量而不是迭代器。