#include<iostream>
#include<string>
using namespace std;
#define max_free 10 //空闲区最大个数
#define max_job 10 //已分分区最大个数
struct table {
float address; //起始地址
float length; //分区长度
string flag;
//0表示空栏目，1表示未分配,作业名则表示分配给某作业。
}free_table[max_free], used_table[max_job];
static float Size = 0; //最小切割长度
void init(table free_table[], table used_table[]) {
/*初始化空闲分区*/
for (int i = 0; i < max_free; i++) {
free_table[i].flag = "0";
used_table[i].flag = "0";
}
int s; //初始空闲分区个数
printf("请输入初始空闲分区的个数：\n");
scanf_s("%d", &s);
for (int i = 0; i < s; i++) {
printf("输入第%d块空闲分区始址、大小：\n", i + 1);
scanf_s("%f%f", &free_table[i].address, &free_table[i].length);
free_table[i].flag = "1";
}
printf("请输入最小可分割长度：\n");
scanf_s("%f", &Size);
printf("\n\n");
}
void sort(table free_table[]) {
/*对空闲区按照内存大小进行排序*/
for (int i = 0; i < max_free - 1; i++) {
if (free_table[i].length > free_table[i + 1].length) {
float tmp; tmp = free_table[i].address; free_table[i].address = free_table[i + 1].address; free_table[i + 1].address = tmp;
float temp; temp = free_table[i].length; free_table[i].length = free_table[i + 1].length; free_table[i + 1].length = temp;
string tan; tan = free_table[i].flag; free_table[i].flag = free_table[i + 1].flag; free_table[i + 1].flag = tan;
}
}
}
void BF(table free_table[], table used_table[]) {
/*最佳适应算法进行内存分配*/
printf("请输入作业名称、内存大小：\n");
float length; //该作业内存大小
string name;
cin >> name >> length;
//对空闲区，按照空闲区从小到大进行排序。
sort(free_table);
bool k = false; //判断是否找到空闲区
for (int i = 0; i < max_free; i++) {
if (free_table[i].flag == "1" && free_table[i].length >= length) {
if (free_table[i].length - length < Size) {
//空闲区不进行切割
free_table[i].flag = name; //空闲区状态设置为作业占用
used_table[i].address = free_table[i].address;
used_table[i].length = free_table[i].length;
used_table[i].flag = name;
k = true;
break;
}
else {
//空闲区进行切割
used_table[i].address = free_table[i].address;
used_table[i].length = length;
used_table[i].flag = name;
free_table[i].address += length;
free_table[i].length -= length;
k = true;
break;
}
}
}
if (k == false)
printf("无可用空闲区！\n");
sort(free_table);
printf("\n\n");
}
void Recycle(table free_table[], table used_table[]) {
printf("请输入内存回收的作业名称：\n");
string name;
cin >> name;
bool k = false; //判断已分配分区中是否有该作业
bool tag = false; //判断是否有相邻空闲区
for (int i = 0; i < max_job; i++) {
if (used_table[i].flag == name) {
for (int j = 0; j < max_free; j++) {
/*判断作业两旁是否有空闲区*/
if ((free_table[j].address + free_table[j].length) == used_table[i].address && free_table[j].flag == "1") {
/*作业上方有空闲区*/
used_table[i].flag = "0"; //将该分区置为空栏目
free_table[j].length += used_table[i].length;
tag = true;
break;
}
if ((used_table[i].address + used_table[i].length) == free_table[j].address && free_table[j].flag == "1") {
/*作业下方有空闲区*/
used_table[i].flag = "0";
free_table[j].address -= used_table[i].length;
free_table[j].length += used_table[i].length;
tag = true;
break;
}
for (int m = j + 1; m < max_free; m++) {
if ((free_table[j].address + free_table[j].length) == used_table[i].address
&& (used_table[i].address + used_table[i].length) == free_table[m].address && free_table[j].flag == "1") {
/*作业上下都有空闲区*/
used_table[i].flag = "0";
free_table[m].flag = "0";
free_table[j].length = used_table[i].length + free_table[m].length;
tag = true;
break;
}
} //end of for
} //end of for
/*没有空闲区合并情况*/
if (tag == false) { //tag判断是否有相邻空闲区
for (int n = 0; n < max_free; n++) {
if (free_table[n].flag == "0") {
used_table[i].flag = "0";
free_table[n].address = used_table[i].address;
free_table[n].length = used_table[i].length;
free_table[n].flag = "1";
break;
}
}
}
k = true; //标志已分配分区中有该作业
break; //如果存在，找到并合并完即可，无需再向下循环，提高效率
} //end of if
} //end of for
if (k == false) {
printf("未找到作业%s，请确定后重新输入！\n", name.c_str());
Recycle(free_table, used_table);
}
sort(free_table);
printf("\n");
}
void Display_free(table free_table[]) {
printf("空闲区：\n");
printf("始址\t大小\t当前状态\n");
for (int i = 0; i < max_free; i++) {
if (free_table[i].flag == "1") {
string state = "未分配";
printf("%.0f\t%.0f\t%s\n",free_table[i].address,free_table[i].length,state.c_str());
}
}
printf("\n\n");
}
void Display_used(table used_table[]) {
printf("已分配分区:\n");
printf("始址\t大小\t当前状态\n");
for (int i = 0; i < max_job; i++) {
if (used_table[i].flag != "0" && used_table[i].flag != "1")
printf("%.0f\t%.0f\t%s\n", used_table[i].address, used_table[i].length, used_table[i].flag.c_str());
}
printf("\n\n");
}
void chose(table free_table[], table used_table[]) {
while (true) {
int q;
printf("请输入操作对应数字完成操作！\n");
printf("1、首次适应算法分配内存\t2、回收作业内存\t3、空闲区信息\n\n4、已分配分区信息\t5、空闲分区初始化\t6、退出\n");
scanf_s("%d", &q);
switch (q) {
case 1:
BF(free_table, used_table);
break;
case 2:
Recycle(free_table, used_table);
break;
case 3:
Display_free(free_table);
break;
case 4:
Display_used(used_table);
break;
case 5:
init(free_table, used_table);
break;
case 6:
exit(0); //正常退出程序
break;
}
}
}
void main() {
init(free_table, used_table);
chose(free_table, used_table);
}