我有 vector 运动
vector<posToMove> movements;
posToMove 是一个结构体:
struct posToMove
{
int fromX;
int fromY;
int toX;
int toY;
};
我想删除移动中的重复项,我该怎么做?
最佳答案
最简单的方法是使用:
movements.erase(std::unique(movements.begin(), movements.end()), movements.end());
但是std::unique
只删除连续 重复的元素,因此您需要对 std::vector
进行排序首先,通过重载 <
和 ==
运算符(operator):
struct posToMove
{
int fromX;
int fromY;
int toX;
int toY;
bool operator < (const posToMove& other) const
{
//declare how 2 variable of type posToMove should be compared with <
return std::make_tuple(fromX, fromY, toX, toY) < std::make_tuple(other.fromX, other.fromY, other.toX, other.toY);
}
bool operator == (const posToMove& other) const
{
//declare how 2 variable of type posToMove should be compared with ==
return std::make_tuple(fromX, fromY, toX, toY) == std::make_tuple(other.fromX, other.fromY, other.toX, other.toY);
}
};
我声明了<
和 ==
运算符 make_tuple()
, 但您也可以将其替换为您选择的比较。
代码:
#include <iostream>
#include <vector>
#include <tuple>
#include <algorithm>
struct posToMove
{
int fromX;
int fromY;
int toX;
int toY;
bool operator < (const posToMove& other) const
{
//declare how 2 variable of type posToMove should be compared with <
return std::make_tuple(fromX, fromY, toX, toY) < std::make_tuple(other.fromX, other.fromY, other.toX, other.toY);
}
bool operator == (const posToMove& other) const
{
//declare how 2 variable of type posToMove should be compared with ==
return std::make_tuple(fromX, fromY, toX, toY) == std::make_tuple(other.fromX, other.fromY, other.toX, other.toY);
}
};
std::vector<posToMove>movements;
int main()
{
movements.push_back({0,1,0,0});
movements.push_back({1,2,5,7});
movements.push_back({3,9,9,6});
movements.push_back({0,1,0,0});
movements.push_back({4,1,8,0});
movements.push_back({1,2,5,7});
std::sort(movements.begin(), movements.end());
std::cout << "After sort : \n";
for (auto x : movements)
{
std::cout << x.fromX << " " << x.fromY << " " << x.toX << " " << x.toY << "\n";
}
std::cout << "\n";
movements.erase(std::unique(movements.begin(), movements.end()), movements.end());
std::cout << "After removing : \n";
for (auto x : movements)
{
std::cout << x.fromX << " " << x.fromY << " " << x.toX << " " << x.toY << "\n";
}
}
结果:
After sort :
0 1 0 0
0 1 0 0
1 2 5 7
1 2 5 7
3 9 9 6
4 1 8 0
After removing :
0 1 0 0
1 2 5 7
3 9 9 6
4 1 8 0
相关:Remove duplicates in vector of structure c++
文档:
erase()
: https://en.cppreference.com/w/cpp/container/vector/erase2
std::unique
: https://en.cppreference.com/w/cpp/algorithm/unique
std::sort
: https://en.cppreference.com/w/cpp/algorithm/sort
重载运算符:https://en.cppreference.com/w/cpp/language/operators
https://stackoverflow.com/questions/67929680/