优化一下代码int fifo_missing_page_num(int* page_seq, int seq_len, int mem_page_num){ int i, j, k, page_faults = 0; int *mem_queue = (int*)malloc(mem_page_num * sizeof(int)); int *available = (int*)calloc(mem_page_num, sizeof(int)); int oldest = 0; for(i = 0; i < seq_len; i++){ int page_num = page_seq[i]; int found = 0; for(j = 0; j < mem_page_num; j++){ if(mem_queue[j] == page_num){ found = 1; break; } } if(!found){ page_faults++; mem_queue[oldest] = page_num; oldest = (oldest + 1) % mem_page_num; } } free(mem_queue); free(available); return page_faults;}

可以考虑使用哈希表来代替当前代码中的线性查找，这样可以将查找的时间复杂度从O(n)降为O(1)。同时，可以将动态分配内存的操作提到函数外部，避免在每次函数调用时都进行内存分配和释放，提高代码效率。优化后的代码如下：

int fifo_missing_page_num(int* page_seq, int seq_len, int mem_page_num, int* mem_queue){
    int i, page_faults = 0;
    int *available = (int*)calloc(mem_page_num, sizeof(int));
    int oldest = 0;
    for(i = 0; i < seq_len; i++){
        int page_num = page_seq[i];
        int found = available[page_num];
        if(!found){
            page_faults++;
            available[mem_queue[oldest]] = 0;
            mem_queue[oldest] = page_num;
            available[page_num] = 1;
            oldest = (oldest + 1) % mem_page_num;
        }
    }
    free(available);
    return page_faults;
}

调用函数时需将mem_queue作为参数传入，mem_queue是一个长度为mem_page_num的数组，用于记录当前的物理内存页表。