Question

我想从头开始实施Stack并遇到问题。我觉得我在编写push方法的参数错误，例如：

public void push(<T> foo){
    myList.add(foo);
}

当我不确定foo将是什么类型时，我还能如何编写参数？

package Stack;
import java.util.*;

public class Stack<T> {

    private List<T> myList;

    public Stack(){
        myList = null;
    }

    public boolean empty(){
        return (myList == null);
    }

    public void push(<T> foo){
        myList.add(foo);
    }
}

Answer 1

public void push(T foo){
    myList.add(foo);
}

您可以阅读有关泛型here的更多信息。

Answer 2

正确的语法是：

public void push(T foo) {
    myList.add(foo);
}

Answer 3

只需要

static struct Point{
public:
    double x, y;
    std::set<std::multiset<Point>*,PointerCompare>occurrences;

    Point(double a, double b){ x = a; y = b; }
    Point(){}
};

struct PointerCompare{
    bool operator()(std::multiset<Point>* a, std::multiset<Point>* b){
        uintptr_t aVal = reinterpret_cast<uintptr_t>(a);
        uintptr_t bVal = reinterpret_cast<uintptr_t>(b);
        return a < b;
    }
};

Answer 4

键入cast foo到Object type

public void push(Object foo){
    myList.add(foo);
}

从头开始实现`Stack`

4 个答案: