他就是个栈,栈就随便写了,贴代码
#include <iostream> #include <stack> #include <string> using namespace std; int main(){ stack<string> stack1,stack2; string str,s1,s2; str="http://www.acm.org/"; stack1.push(str); while(cin>>s1){ if(s1=="QUIT") break; if(s1=="VISIT"){ cin>>s2; cout<<s2<<endl; stack1.push(s2); while(!stack2.empty()) stack2.pop(); } else if(s1=="BACK"){ if(stack1.size()>=2){ stack2.push(stack1.top()); stack1.pop(); cout<<stack1.top()<<endl; } else puts("Ignored"); } else { if(!stack2.empty()){ cout<<stack2.top()<<endl; stack1.push(stack2.top()); stack2.pop(); } else puts("Ignored"); } } return 0; }
poj 1028
时间: 2024-11-04 15:02:21