day1

1.剑指 Offer 09. 用两个栈实现队列

 1 class CQueue {
 2 public:
 3     stack<int> s1,s2;
 4     CQueue() {
 5        
 6     }
 7     
 8     void copy(stack<int>& a,stack<int>& b){
 9         while(a.size()){
10             int tmp = a.top();
11             a.pop();
12             b.push(tmp);
13         }
14     }
15 
16     void appendTail(int value) {
17       s1.push(value);
18     }
19     
20     int deleteHead() {
21       int result;
22       if(s2.size()){
23           result = s2.top();
24           s2.pop();
25       }
26       else{
27         if(s1.size()){
28           copy(s1,s2);
29           result = s2.top();
30           s2.pop();
31         }
32         else
33          result = -1;
34       }
35       return result;
36     }
37 };
38 
39 /**
40  * Your CQueue object will be instantiated and called as such:
41  * CQueue* obj = new CQueue();
42  * obj->appendTail(value);
43  * int param_2 = obj->deleteHead();
44  */

2.剑指 Offer 30. 包含 min 函数的栈

 1 class MinStack {
 2 public:
 3     /** initialize your data structure here. */
 4     stack<int> stk1,stk2;
 5     MinStack() {
 6       
 7     }
 8     
 9     void push(int x) {
10       stk1.push(x);
11       if(stk2.empty() || stk2.top() >= x)
12        stk2.push(x);
13     }
14     
15     void pop() {
16       if(stk1.top() == stk2.top())
17        stk2.pop();
18       stk1.pop();
19     }
20     
21     int top() {
22       return stk1.top();
23     }
24     
25     int min() {
26       return stk2.top();
27     }
28 };
29 
30 /**
31  * Your MinStack object will be instantiated and called as such:
32  * MinStack* obj = new MinStack();
33  * obj->push(x);
34  * obj->pop();
35  * int param_3 = obj->top();
36  * int param_4 = obj->min();
37  */

 

标签：obj,int,s2,top,pop,day1,stk2
来源： https://www.cnblogs.com/balabalabubalabala/p/16411923.html