題目描述
定義棧的數據結構,請在該類型中實現一個能夠得到棧中所含最小元素的min函數(時間複雜度應爲O(1))。
代碼
class Solution {
public:
void push(int value) {
datestack.push(value);
if(minstack.empty())
minstack.push(value);
else
if(value<=minstack.top())
minstack.push(value);
}
void pop() {
if(datestack.empty())
return;
if(minstack.top() == datestack.top())
minstack.pop();
datestack.pop();
}
int top() {
return datestack.top();
}
int min() {
return minstack.top();
}
private:
stack<int>datestack;
stack<int>minstack;
};