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implement_queue_using_stacks.cpp
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implement_queue_using_stacks.cpp
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/*
* =====================================================================================
*
* Filename: implement_queue_using_stacks.cpp
*
* Description: 232. Implement Queue using Stacks.
* https://leetcode.com/problems/implement-queue-using-stacks
*
* Version: 1.0
* Created: 10/07/2021 17:27:25
* Revision: none
* Compiler: gcc
*
* Author: [email protected]
* Organization:
*
* =====================================================================================
*/
#include <cstdio>
#include <stack>
class MyQueue {
public:
MyQueue() {}
void push(int x) { stack1_.push(x); }
int pop() {
const int val = peek();
stack2_.pop();
return val;
}
int peek() {
if (stack2_.empty()) {
while (!stack1_.empty()) {
stack2_.push(stack1_.top());
stack1_.pop();
}
}
return stack2_.top();
}
bool empty() { return (stack1_.empty() && stack2_.empty()); }
private:
std::stack<int> stack1_;
std::stack<int> stack2_;
};
int main(int argc, char* argv[]) {
MyQueue queue;
queue.push(1);
queue.push(2);
queue.push(3);
const int val = queue.peek();
printf("val = %d\n", val);
return 0;
}