我的代码解释一个二进制文件并从中读取数据。
我无法找到此错误的原因。编译器终止并抛出
bad_alloc(terminate called after throwing an instance of 'std::bad_alloc'
what(): std::bad_alloc)
我试过寻找无限递归、语法错误等。我想知道这个问题是否经常发生在这个任务中？
下面是我的代码，附有更好理解的说明：
步骤：
- 打开二进制文件进行阅读。
- 读取文件的前 4 个字节以获取文件中的船只数量。
- 遍历文件中的每艘船。
- 读取船名长度，读取船名字符串数据。
- 读取船舶等级长度，读取等级字符串数据。
- 读取船长、护盾容量和最大曲速。
- 读取船上的武器数量。
- 遍历船上的每件武器。
- 读取武器名称长度，读取武器名称字符串数据。
- 读取武器的额定功率和功耗。
- 将船舶和武器数据存储在一个向量中。
- 关闭文件。
功能：
- 打印所有的船
- 用最强大的武器打印星际飞船
- 打印最强大的船（所有武器的最高综合额定功率）
- 打印最弱的船（实际拥有武器的船）
- 打印非武装船只
#include <iostream>
#include <fstream>
#include <string>
#include <climits>
#include <vector>
using namespace std;
struct Weapon {
string name;
int power_rating;
float power_consumption;
};
struct Ship {
string name;
string ship_class;
int length;
int shield_capacity;
float warp_speed;
vector<Weapon> weapons;
};
// Function to print all the ships
void printAllShips(const vector<Ship>& ships) {
for (const Ship& ship : ships) {
cout << "Name: " << ship.name << endl;
cout << "Class: " << ship.ship_class << endl;
cout << "Length: " << ship.length << endl;
cout << "Shield capacity: " << ship.shield_capacity << endl;
cout << "Maximum Warp: " << ship.warp_speed << endl;
cout << "Armaments: " << endl;
if (ship.weapons.empty()) {
cout << "Unarmed" << endl;
} else {
int totalPower = 0;
for (const Weapon& weapon : ship.weapons) {
cout << weapon.name << ", " << weapon.power_rating << ", " << weapon.power_consumption << endl;
totalPower += weapon.power_rating;
}
cout << "Total firepower: " << totalPower << endl;
}
cout << endl;
}
}
// Function to print the ship with the most powerful weapon
void printShipWithMostPowerfulWeapon(const vector<Ship>& ships) {
const Ship* maxWeaponShip = nullptr;
const Weapon* maxWeapon = nullptr;
int maxPower = 0;
for (const Ship& ship : ships) {
for (const Weapon& weapon : ship.weapons) {
if (weapon.power_rating > maxPower) {
maxPower = weapon.power_rating;
maxWeaponShip = &ship;
maxWeapon = &weapon;
}
}
}
if (maxWeaponShip == nullptr) {
cout << "No ships have weapons." << endl;
} else {
cout << "Ship with most powerful weapon: " << maxWeaponShip->name << endl;
cout << "Weapon name: " << maxWeapon->name << endl;
cout << "Weapon power rating: " << maxWeapon->power_rating << endl;
cout << "Weapon power consumption: " << maxWeapon->power_consumption << endl;
}
}
// Function to print the most powerful ship (highest combined power rating of all weapons)
void printMostPowerfulShip(const vector<Ship>& ships) {
const Ship* maxPowerShip = nullptr;
int maxPower = INT_MIN;
for (const Ship& ship : ships) {
int totalPower = 0;
for (const Weapon& weapon : ship.weapons) {
totalPower += weapon.power_rating;
}
if (totalPower > maxPower) {
maxPower = totalPower;
maxPowerShip = &ship;
}
}
if (maxPowerShip == nullptr) {
cout << "No ships have weapons." << endl;
} else {
cout << "Most powerful ship: " << maxPowerShip->name << endl;
cout << "Total power rating: " << maxPower << endl;
}
}
// Function to print the weakest ship (out of ships that actually have weapons)
void printWeakestShip(const vector<Ship>& ships) {
const Ship* minPowerShip = nullptr;
int minPower = INT_MAX;
for (const Ship& ship : ships) {
if (!ship.weapons.empty()) {
int totalPower = 0;
for (const Weapon& weapon : ship.weapons) {
totalPower += weapon.power_rating;
}
if (totalPower < minPower) {
minPower = totalPower;
minPowerShip = &ship;
}
}
}
if (minPowerShip == nullptr) {
cout << "No ships have weapons." << endl;
} else {
cout << "Least powerful ship: " << minPowerShip->name << endl;
cout << "Total power rating: " << minPower << endl;
}
}
vector<Ship> readBinFile(string fileName) {
vector<Ship> ships;
ifstream file(fileName, ios::binary);
if (!file.is_open()) {
cout << "Error: Could not open file " << fileName << endl;
return ships;
}
int numShips;
file.read(reinterpret_cast<char*>(&numShips), sizeof(numShips));
for (int i = 0; i < numShips; i++) {
Ship ship;
int nameLength;
file.read(reinterpret_cast<char*>(&nameLength), sizeof(nameLength));
ship.name.resize(nameLength);
file.read(&ship.name[0], nameLength);
int classLength;
file.read(reinterpret_cast<char*>(&classLength), sizeof(classLength));
ship.ship_class.resize(classLength);
file.read(&ship.ship_class[0], classLength);
file.read(reinterpret_cast<char*>(&ship.length), sizeof(ship.length));
file.read(reinterpret_cast<char*>(&ship.shield_capacity), sizeof(ship.shield_capacity));
file.read(reinterpret_cast<char*>(&ship.warp_speed), sizeof(ship.warp_speed));
int numWeapons;
file.read(reinterpret_cast<char*>(&numWeapons), sizeof(numWeapons));
for (int j = 0; j < numWeapons; j++) {
Weapon weapon;
int weaponNameLength;
file.read(reinterpret_cast<char*>(&weaponNameLength), sizeof(weaponNameLength));
weapon.name.resize(weaponNameLength);
file.read(&weapon.name[0], weaponNameLength);
file.read(reinterpret_cast<char*>(&weapon.power_rating), sizeof(weapon.power_rating));
file.read(reinterpret_cast<char*>(&weapon.power_consumption), sizeof(weapon.power_consumption));
ship.weapons.push_back(weapon);
}
ships.push_back(ship);
}
file.close();
return ships;
}
int main()
{
cout << "Which file(s) to open?\n";
cout << "1. friendlyships.shp" << endl;
cout << "2. enemyships.shp" << endl;
cout << "3. Both files" << endl;
int option = 3;
vector<Ship> allShips;
/* Load files here */
if (option == 1){
allShips = readBinFile("friendlyships.shp");
}
if (option == 2){
allShips = readBinFile("enemyships.shp");
}
if (option == 3){
allShips = readBinFile("friendlyships.shp");
vector<Ship> set2 = readBinFile("enemyships.shp");
allShips.insert(allShips.end(), set2.begin(), set2.end());
}
cout << "1. Print all ships" << endl;
cout << "2. Starship with the strongest weapon" << endl;
cout << "3. Strongest starship overall" << endl;
cout << "4. Weakest ship (ignoring unarmed)" << endl;
cout << "5. Unarmed ships" << endl;
int choice = 1;
if (choice == 1){
printAllShips(allShips);
}
if (choice == 2){
printShipWithMostPowerfulWeapon(allShips);
}
if (choice == 3){
printMostPowerfulShip(allShips);
}
if (choice == 4){
printWeakestShip(allShips);
}
if (choice == 5){
}
return 0;
}
你不能读这样的字符串
file.read(&weapon.name[0], weaponNameLength);
你需要
file.read(&weapon.name.data()[0], weaponNameLength);
或读入中间
char[MAX]