牛客周赛19 D 神器大师泰兹瑞与威穆 (模拟)

模拟vim (雾
用两个栈s1, s2去模拟，s2的top位置就是光标。这样无论删除还是添加都很方便

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<map>
#include<stack>
#include<queue>
#include<vector>
#include<string>
#include<fstream>
// #include<unordered_map>
using namespace std;
#define rep(i, a, n) for(int i = a; i <= n; ++ i)
#define per(i, a, n) for(int i = n; i >= a; -- i) 
#define px first
#define py second  
typedef long long ll;
typedef pair<int,int>PII;
const int N = 2e5 + 10;
const ll mod = 998244353;
const double Pi = acos(- 1.0);
const int INF = 0x3f3f3f3f;
const int G = 3, Gi = 332748118;
ll qpow(ll a, ll b) { ll res = 1; while(b){ if(b & 1) res = (res * a) % mod; a = (a * a) % mod; b >>= 1;} return res; }
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
//

stack<char> s1,s2;
char t[N];
int num[50];

int main()
{
    scanf("%s",t + 1);
    int sn = strlen(t + 1);
    for(int i = sn; i >= 1; -- i){
        s2.push(t[i]);
        num[t[i] - 'a'] ++;
    }
    scanf("%s",t + 1);
    int tn = strlen(t + 1);    
    int l = 1, flag = 0;
    for(int i = 1; i <= tn; ++ i){
        char op = t[i]; 
        if(flag){   //Insert Mode
            if(op == 'e'){
                flag = 0;
                continue;
            }
            s1.push(op);
        }
        else{       // Normal Mode
            if(op == 'i'){
                flag = 1;
                continue;
            }
            else if(op == 'f' && s2.size()){
                op = t[++ i];
                if(!num[op - 'a'] || (num[op - 'a'] == 1 && s2.top() == op)) continue;
                num[s2.top() - 'a'] --;
                s1.push(s2.top()); s2.pop();
                while(s2.size() && s2.top() != op){
                    num[s2.top() - 'a'] --;
                    s1.push(s2.top()); s2.pop();                    
                }
            }
            else if(op == 'x' && s2.size()){
                num[s2.top() - 'a'] -- , s2.pop();
            }
            else if(op == 'h' && s1.size()){
                num[s1.top() - 'a'] ++;
                s2.push(s1.top()), s1.pop();
            }
            else if(op == 'l' && s2.size()){
                num[s2.top() - 'a'] --;
                s1.push(s2.top()), s2.pop();
            }
        }
    }
    while(s1.size()){
        s2.push(s1.top()); s1.pop();
    }
    while(s2.size()){
        printf("%c",s2.top()); s2.pop();
    }
    printf("\n");
    return 0;
}