我有以下代码
#include <iostream>
#include <vector>
using namespace std;
int distance(vector<int>& set1, vector<int>& set2) {
int distance = 0;
unsigned int i1 = 0;
unsigned int i2 = 0;
while(i1 < set1.size() && i2 < set2.size()) {
if(set1[i1] == set2[i2]) {
++i1; ++i2;
} else {
++distance;
set1[i1] < set2[i2] ? ++i1 : ++i2;
}
}
unsigned int zero = 0;
distance += std::max(set1.size() - i1, zero) + std::max(set2.size() - i2, zero);
}
int main() {
vector<vector<int> > frequent_sets;
vector<int> vector3;
vector3.push_back(1);vector3.push_back(2);vector3.push_back(3);
vector<int> vector2;
vector2.push_back(1);vector2.push_back(2);
frequent_sets.push_back(vector3);
frequent_sets.push_back(vector3);
frequent_sets.push_back(vector2);
frequent_sets.push_back(vector3);
for(vector<vector<int> >::iterator itouter = frequent_sets.begin(); itouter != frequent_sets.end(); ++itouter)
for(vector<vector<int> >::iterator itinner = (itouter + 1); itinner != frequent_sets.end(); ++itinner)
if(distance(*itinner, *itouter) == 0) {
cout << "Hey" << endl;
}
}
当我尝试编译时，我收到错误：
make all Building文件：../ src / TestIterator.cpp调用：GCC C编译器g -O0 -g3 -Wall -c -fmessage-length = 0 -MMD -MP -MF“src / TestIterator.d”-MT“ src / TestIterator.d“ - o”src / TestIterator.o“”../ src /TestIterator.cpp“/ usr / include / c /4.3/bits/stl_iterator_base_types.h：在'std :: iterator_traits >>的实例化中'：../ src / TestIterator.cpp：50：从这里实例化/ usr / include / c /4.3/bits/stl_iterator_base_types.h:133：错误：'class std :: vector'中没有名为'iterator_category'的类型make ：*** [src / TestIterator.o]错误1
为什么是这样？当我用 itinner->size() == itouter->size() 替换 distance(*itouter, *itinner) == 0 时，代码正在编译并运行正常 .
2 回答
你
distance函数与std中的函数发生冲突 . 通常不建议's why it'在您的代码中编写using namespace std;. 尝试删除该功能或将您的功能重命名为my_distance.它正在尝试使用
namespace std中定义的distance算法 . 如果你想调用你的距离函数，请使用::distance