在 vector 中使用删除的 C++ 段错误

Question

我在我的代码中遇到段错误，我想知道为什么。我正在猜测它与 vector.erase() 函数有关。

#include <iostream>
#include <vector>
#include <math.h>

long long gcd(long long x, long long y);
std::vector<long long> factor(long long x);
typedef std::vector<long long> vectorNum;

int main(int argc, const char * argv[])
{

    // insert code here...
    long long unFriendly;
    long long friendly;
    long long counter = 0;
    std::cin >> unFriendly;
    std::cin >> friendly;
    vectorNum n;
    n = factor(friendly);

    for(long long x = 0;x < unFriendly;x++){
        long long num = 0;

        std::cin >> num;
        counter = gcd(friendly, num);
        for(long long y = n.size() - 1;y >= 0;y--){
            vectorNum temp(n);
            if(counter % n.at(y) == 0){
                n.erase(n.begin() + y);
            }
        }
    }

    std::cout<<n.size();
    n.clear();

}

long long gcd(long long x, long long y){
    while(y != 0){
        long long a = x % y;
        x = y;
        y = a;
    }
    return x;
}

std::vector<long long> factor(long long x){
    long long y;
    long long root = sqrt(x);
    std::vector<long long> vectorSet;
    for(y = 2; y <= root;y++){
        if(x % y == 0){
            vectorSet.push_back(y);
            vectorSet.push_back(x / y);

        }
    }
    vectorSet.push_back(x);
    return vectorSet;
}

任何类型的见解都是完美的!提前致谢。这是被调用的两个函数。 gcd() 和 factors() 均按要求运行。

Answer 1

for(long long x = 0;x < unFriendly;x++){
    long long num = 0;

    std::cin >> num;
    counter = gcd(friendly, num);
    for(long long y = n.size() - 1;y >= 0;y--) {  // <-- n.size() == 0, 0U - 1 is huge
        vectorNum temp(n);
        if(counter % n.at(y) == 0){  // <-- y is huge, throws std::out_of_range
            n.erase(n.begin() + y);
        }
    }
}

我强烈建议在调试器下运行您的代码。运行代码时，Visual Studio 调试器很快显示: