题目描述
定义栈的数据结构，请在该类型中实现一个能够得到栈中所含最小元素的min函数（时间复杂度应为O（1））。
我的解答
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import java.util.Stack;
public class Solution {
Stack<Integer> stack = new Stack();
Stack<Integer> minStack = new Stack();
public void push(int node) {
if (minStack.isEmpty()) {
minStack.push(node);
}else if (minStack.peek() > node) {
minStack.push(node);
}
stack.push(node);
}
public void pop() {
if (stack.peek() == minStack.peek()){
minStack.pop();
}
stack.pop();
}
public int top() {
return stack.peek();
}
public int min() {
return minStack.peek();
}
}
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