-
Notifications
You must be signed in to change notification settings - Fork 77
/
ATaleOfTwoStacks.cpp
59 lines (53 loc) · 1.58 KB
/
ATaleOfTwoStacks.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <stack>
#include <queue>
using namespace std;
class MyQueue {
public:
stack<int> stack_newest_on_top, stack_oldest_on_top;
void push(int x) {
stack_newest_on_top.push(x);
}
void pop() {
if (stack_oldest_on_top.empty()) {
// copy over and pop
while (!stack_newest_on_top.empty()) {
stack_oldest_on_top.push(stack_newest_on_top.top());
stack_newest_on_top.pop();
}
}
stack_oldest_on_top.pop();
}
int front() {
if (stack_oldest_on_top.empty()) {
// copy over and pop
while (!stack_newest_on_top.empty()) {
stack_oldest_on_top.push(stack_newest_on_top.top());
stack_newest_on_top.pop();
}
}
return stack_oldest_on_top.top();
}
};
int main() {
MyQueue q1;
int q, type, x;
cin >> q;
for(int i = 0; i < q; i++) {
cin >> type;
if(type == 1) {
cin >> x;
q1.push(x);
}
else if(type == 2) {
q1.pop();
}
else cout << q1.front() << endl;
}
/* Enter your code here. Read input from STDIN. Print output to STDOUT */
return 0;
}