50162. RPG Queue

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

#define max(a,b) ((a)>(b)?(a):(b))
#define min(a,b) ((a)<(b)?(a):(b))

typedef struct{
    int arr[5000];
    int front, rear;
    int size;
} cir_array;

cir_array a[3];

int step(int x){
    return (x + 1) % 5000;
}

int main(){
    for(int i = 0; i < 3; i++) a[i].front = 0, a[i].rear = 0, a[i].size = 0;

    int num;
    while(scanf("%d", &num) != EOF){
        cir_array* this_arr = &a[num % 3];
        this_arr->arr[this_arr->rear] = num;
        this_arr->rear= step(this_arr->rear);
        this_arr->size += 1;

        if(a[0].size >= 3 && a[1].size >= 1 && a[2].size >= 1){
            for(int i = 0; i < 3; i++){
                printf("%d ", a[0].arr[a[0].front]);
                a[0].front = step(a[0].front);
                a[0].size -= 1;
            }
            printf("%d %d\n", a[1].arr[a[1].front], a[2].arr[a[2].front]);
            a[1].front = step(a[1].front); a[1].size -= 1;
            a[2].front = step(a[2].front); a[2].size -= 1;
        }
    }
}