vs出错dev－c++通过

比较两个vector
#include <iostream>
#include <vector>
using namespace std;

int main ()
{
    vector<int> vec1,vec2;
    int val;

    cout << "Enter the two vectors(-1 to end):" << endl;
    cin >> val;
    while ( val != -1 ) {
        vec1.push_back(val);
        cin >> val;
    }
    cin >> val;
    while ( val != -1 ) {
        vec2.push_back(val);
        cin >> val;
    }
    if ( vec1.size() != vec2.size() )
        cout << "Not equal" << endl;
    else if ( vec1.size() == 0 )
        cout << "Equal" << endl;
    else
    {
        vector<int>::iterator iter1,iter2;
        iter1 = vec1.begin();
        iter2 = vec2.begin();
        while ( *iter1 == *iter2 && iter1 != vec1.end() && iter2 != vec2.end() ) {
            ++iter1;
            ++iter2;
        }
        if ( iter1 == vec1.end() )
            cout << "Equal" << endl;
        else
            cout << "Not equal" <<endl;
    }

    return 0;
}
此程序编译通过，在visual studio 2005中调试出错，但在dev-c++5中调试成功，不知为什么，望高手赐教？