PlateTOI1.cpp

#include <bits/stdc++.h>

using namespace std;

int a[10100];
int q[1010];
int fr, en;

int main(){
    int n,m,c,s,i,k;
    char opr;

    scanf("%d %d", &n , &m);

    while(m--){
        scanf("%d %d", &c, &s);
        a[s] = c;
    }

    while(1){
        scanf(" %c", &opr);
        if(opr == 'X'){
        printf("0\n");
        return 0;
        }
        if(opr == 'E'){
            scanf("%d", &n);
            k = en;
            for(i = en-1 ; i >= fr ; i--){
                if(a[n] == a[q[i]]){
                    k = i+1;
                    break;
                }
            }
            for(i = en-1 ; i >= k ; i--){
                q[i+1] = q[i];
            }
                q[k] = n;
                en++;
        }
        if(opr == 'D'){
            if(fr == en){
                printf("empty\n");
            }
            else{
                printf("%d\n", q[fr++]);
            }
        }
    }
    return 0;
}