题解 | #【模板】队列#

#include <stdio.h>
#include <malloc.h>
#include <stdlib.h>
#include <string.h>
#define MAX 100000
int main() {
    int front = 0, rear = 0;
    int Q[MAX] = {0};
    int n;
    scanf("%d", &n);
    while (n--) {
        char a[10];
        scanf("%s",a);
        if (!strcmp(a, "push")) {
            int x;
            scanf("%d", &x);
            Q[rear++] = x;
        }
        if (!strcmp(a, "pop")) {
            if (front == rear)
                printf("error\n");
            else {
                printf("%d\n", Q[front++]);
            }

        }
        if (!strcmp(a, "front")) {
            if (front == rear)
                printf("error\n");
            else {
                printf("%d\n", Q[front]);
            }

        }

    }
    return 0;
}