比较两个向量中未排序的元素

Question

我是 C++ 新手，我正在尝试将两个未排序的向量元素相互比较并确定它们是否匹配。

例如： 1 4 9 16 9 7 4 9 11 和 11 11 7 9 16 4 1 这些将被视为匹配。

我尝试过使用 firstVector == secondVector，但是当它们的向量未排序时不起作用，我特别想在它们未排序但正在苦苦挣扎时比较它们。

int main() {
int incorrectMatches = 0;
int totalMatches = 0;
int input = 0;
vector <int> firstVector;
vector <int> secondVector;

do {
    cout << "Please enter a number for first vector:  ";
    cin >> input;
    firstVector.push_back(input);
    cout << endl;
} 

while (input > 0);

input = 0;

firstVector.pop_back();

do {
    cout << "Please enter a number for second vector: ";
    cin >> input;
    secondVector.push_back(input);
    cout << endl;
} 

while (input > 0);


secondVector.pop_back();



for (int loop = 0; loop < firstVector.size(); loop++) {
    cout << firstVector[loop] << " ";
}

cout << endl;
for (int loop = 0; loop < secondVector.size(); loop++) {
    cout << secondVector[loop] << " ";
}

cout << endl;
int vectorSize = firstVector.size();

for (int i = 0; i < vectorSize; i++) {
    if (firstVector[i] == secondVector[i]) {
        totalMatches = totalMatches++;
    }
    else {
        incorrectMatches = incorrectMatches++;
    }
}

cout << "There were " << totalMatches << " matches." << endl;

cout << "There were " << incorrectMatches << " incorrect matches";

/*
if (firstVector == secondVector) {
    cout << "Your vectors match!";
}

else{
    cout << "Your vectors don't match!";
}

*/
/*
for (int i = 0; i < input; i++) {
    cout << "Please enter a number (1-9): ";
    myVector.push_back(input);
    cout << endl;

    myVector[i] = i;

    cout << "Vector entry: " << myVector[i] << endl;

}

*/

system("pause");
return 0;}

Answer 1

由于重复无关紧要，您可以简单地将向量的元素分别插入单独的std::set，然后使用operator == 比较集合。我认为集合的使用最能表达您的程序的意图：

int main() {

    vector<int> v1 =  { 1, 4, 9, 16, 9, 7, 4, 9, 11 };
    vector<int> v2 =  { 11, 11, 7, 9, 16, 4, 1 };

    set<int> s1;
    s1.insert(v1.begin(), v1.end());

    set<int> s2;
    s2.insert(v2.begin(), v2.end());

    bool isEqual = (s1 == s2);
    cout << "v1 and v2 are " << (isEqual ? "" : "not ") << "equal." << endl;

    return 0;

}