计导笔试最后一道大题

菜鸡的代码，还有很多可以简化的地方，只是笔试没时间优化，现在也懒得优化，便作罢，就照搬了上来，请大佬指正

手写到自闭。。

示例代码

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

struct graph
{
    char type[10];
    int *start;
    int used[2000];
    int state;
    int real_size;
};

struct graph *configMemory(int size);
int * getMemory(int size, struct graph *graphs);
void freeMemory(int *ptr, struct graph *graphs);
void random(int num, struct graph *graphs);

struct graph *configMemory(int size)
{
    int i, j;
    int *pool = (int *)malloc(sizeof(int) * size);
    struct graph *graphs = (struct graph *)malloc(sizeof(struct graph) * 3);
    int small, mid, big;
    small = size / 3 / 50;
    mid = size / 3 / 100;
    big = size / 3 / 200;
    strcpy(graphs[0].type, "small");
    strcpy(graphs[1].type, "mid");
    strcpy(graphs[2].type, "big");
    graphs[0].start = pool;
    graphs[1].start = pool + small * 50;
    graphs[2].start = pool + mid * 100;
    for (i = 0; i < 2000; i++)
    {
        for (j = 0; j < 3; j++)
        {
            graphs[j].used[i] = 0;
        }
    }
    graphs[0].state = 0;
    graphs[1].state = 0;
    graphs[2].state = 0;
    graphs[0].real_size = small * 50;
    graphs[1].real_size = mid * 100;
    graphs[2].real_size = big * 200;
    return graphs;
}

int * getMemory(int size, struct graph *graphs)
{
    if (size <= 50)
    {
        if (graphs[0].state * 50 < graphs[0].real_size)
        {
            for (int i = 0; i < graphs[0].real_size / 50; i++)
            {

                if (graphs[0].used[i] == 0)
                {
                    graphs[0].used[i] = 1;
                    graphs[0].state++;
                    return graphs[0].start + i * 50;
                }
            }
        }
        else
        {
            return NULL;
        }
    }
    else if (size <= 100)
    {
        if (graphs[1].state * 100 < graphs[1].real_size)
        {
            for (int i = 0; i < graphs[1].real_size / 100; i++)
            {

                if (graphs[1].used[i] == 0)
                {
                    graphs[1].used[i] = 1;
                    graphs[1].state++;
                    return graphs[1].start + i * 100;
                }
            }
        }
        else
        {
            return NULL;
        }
    }
    else if (size <= 200)
    {
        if (graphs[2].state * 200 < graphs[2].real_size)
        {
            for (int i = 0; i < graphs[2].real_size / 200; i++)
            {

                if (graphs[2].used[i] == 0)
                {
                    graphs[2].used[i] = 1;
                    graphs[2].state++;
                    return graphs[2].start + i * 200;
                }
            }
        }
        else
        {
            return NULL;
        }
    }
}

void freeMemory(int *ptr, struct graph *graphs)
{
    if (ptr < graphs[1].start)
    {
        graphs[0].state--;
        graphs[0].used[(ptr - graphs[0].start) / 50] = 0;
    }
    else if (ptr < graphs[2].start)
    {
        graphs[1].state--;
        graphs[1].used[(ptr - graphs[1].start) / 100] = 0;
    }
    else
    {
        graphs[2].state--;
        graphs[2].used[(ptr - graphs[2].start) / 200] = 0;
    }
}

void random(int num, struct graph *graphs)
{
    int i;
    int *used = (int *)malloc(sizeof(int) * num);
    for (i = 0; i < num; i++)
    {
        used[i] = 0;
    }
    int **ptr = (int **)malloc(sizeof(int*) * num);
    for (i = 0; i < num; i++)
    {
        int size = rand() % 150 + 51;
        int *p = getMemory(size, graphs);
        if (p)
        {
            printf("%d %d %p\n", i + 1, size, p);
            used[i] = 1;
            ptr[i] = p;
        }
        else
        {
            printf("%d %d NULL\n", i + 1, size);
        }
    }
    for (i = 0; i < num; i++)
    {
        if (used[i])
        {
            freeMemory(ptr[i], graphs);
        }
    }
}

int main()
{
    int size;
    scanf("%d", &size);
    struct graph *graphs = configMemory(size);
    int num;
    scanf("%d", &num);
    random(num, graphs);
    system("pause");
    return 0;
}