LeetCode（剑指 Offer）- 30. 包含min函数的栈

Posted 2022-02-17 程序员牧码

题目链接：点击打开链接

题目大意：略。

解题思路：略。

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AC 代码

• Java

// 解决方案(1)
class MinStack 

    private final int[] data;

    private final int[] minData;

    private int p;

    private int minP;

    /** initialize your data structure here. */
    public MinStack() 
        data = new int[20000];
        minData = new int[20000];
        p = -1;
        minP = -1;
    

    public void push(int x) 
        data[++p] = x;
        if (-1 == minP || minData[minP] >= x) 
            minData[++minP] = x;
        
    
    
    public void pop() 
        int cur = top();
        data[p--] = 0;
        if (cur == minData[minP]) 
            minData[minP--] = 0;
        
    
    
    public int top() 
        return data[p];
    
    
    public int min() 
        return minData[minP];
    


// 解决方案(2)
class MinStack 
    Stack<Integer> A, B;
    public MinStack() 
        A = new Stack<>();
        B = new Stack<>();
    
    public void push(int x) 
        A.add(x);
        if(B.empty() || B.peek() >= x)
            B.add(x);
    
    public void pop() 
        if(A.pop().equals(B.peek()))
            B.pop();
    
    public int top() 
        return A.peek();
    
    public int min() 
        return B.peek();
    


/**
 * Your MinStack object will be instantiated and called as such:
 * MinStack obj = new MinStack();
 * obj.push(x);
 * obj.pop();
 * int param_3 = obj.top();
 * int param_4 = obj.min();
 */

• C++

class MinStack 
public:
    stack<int> A, B;
    MinStack() 
    void push(int x) 
        A.push(x);
        if(B.empty() || B.top() >= x)
            B.push(x);
    
    void pop() 
        if(A.top() == B.top())
            B.pop();
        A.pop();
    
    int top() 
        return A.top();
    
    int min() 
        return B.top();
    
;