标签:min 最小栈 element constant supports
Design a stack that supports push, pop, top, and retrieving the minimum element in constant time.
push(x) – Push element x onto stack.
pop() – Removes the element on top of the stack.
top() – Get the top element.
getMin() – Retrieve the minimum element in the stack.
思路:需要两个栈,一个用来作为一般的栈,另一个用来存放进栈到某一位置的当前站内最小元素,代码如下:
Code(c++):
class MinStack {
public:
std::stack<int> stk;
std::stack<int> min;
void push(int x) {
stk.push(x);
if(min.empty() || (!min.empty() && x <= min.top())){
min.push(x);
}
}
void pop() {
if(!stk.empty()){
if(stk.top() == min.top())min.pop();
stk.pop();
}
}
int top() {
if(!stk.empty())
return stk.top();
}
int getMin() {
if(!stk.empty()) return min.top();
}
};
标签:min 最小栈 element constant supports
原文地址:http://blog.csdn.net/dream_angel_z/article/details/46467475