题解 | #【模板】循环队列#

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
typedef struct Queuelink {
    int front;
    int rear;
    int maxsize;
    int* data;
} QueueLink;
void QueueInit(QueueLink* Q, int max) {
    Q->data = (int*)malloc(sizeof(int) * (max+1));
    Q->front = 0;
    Q->rear = 0;
    Q->maxsize = max+1;
}
void Queuepush(QueueLink* Q, int x) {
    if ((Q->rear + 1) % Q->maxsize == Q->front) {
        printf("full\n");
        return;
    }
    Q->data[Q->rear] = x;
    Q->rear = (Q->rear + 1) % Q->maxsize;
}
void Queuefront(QueueLink* Q) {
    if (Q->front == Q->rear) {
        printf("empty\n");
        return;
    }
    printf("%d\n", Q->data[Q->front]);
}
void Queuepop(QueueLink* Q) {
    if (Q->front == Q->rear) {
        printf("empty\n");
        return;
    }
    printf("%d\n", Q->data[Q->front]);
    Q->front = (Q->front + 1) % Q->maxsize;
}
int main() {
    int a, q, n;
    char str[6];
    QueueLink Q;
    scanf("%d %d", &n, &q);
    QueueInit(&Q, n);
    for (int i = 0; i < q; i++) {
        scanf("%s %d", str, &a);
        if (strcmp(str, "pop") == 0) {
            Queuepop(&Q);
        } else if (strcmp(str, "front") == 0) {
            Queuefront(&Q);
        } else if (strcmp(str, "push") == 0) {
            Queuepush(&Q, a);
        }
    }
    return 0;
}