动态分区分配算法代码c语言

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

#define MAX_SIZE 100

typedef struct {
    int start_addr;
    int size;
    int is_free;
} Partition;

Partition partitions[MAX_SIZE];
int num_partitions = 0;

void init_partitions() {
    num_partitions = 1;
    partitions[0].start_addr = 0;
    partitions[0].size = MAX_SIZE;
    partitions[0].is_free = 1;
}

void print_partitions() {
    printf("Partitions:\n");
    for (int i = 0; i < num_partitions; i++) {
        printf("Partition %d: start_addr=%d, size=%d, is_free=%d\n", i, partitions[i].start_addr, partitions[i].size, partitions[i].is_free);
    }
}

int allocate_partition(int size) {
    for (int i = 0; i < num_partitions; i++) {
        if (partitions[i].is_free && partitions[i].size >= size) {
            int start_addr = partitions[i].start_addr;
            partitions[i].start_addr += size;
            partitions[i].size -= size;
            if (partitions[i].size == 0) {
                partitions[i].is_free = 0;
            }
            else {
                Partition new_partition = {start_addr + size, partitions[i].size, 1};
                partitions[num_partitions++] = new_partition;
            }
            return start_addr;
        }
    }
    return -1;
}

void deallocate_partition(int start_addr) {
    for (int i = 0; i < num_partitions; i++) {
        if (partitions[i].start_addr == start_addr) {
            partitions[i].is_free = 1;
            if (i > 0 && partitions[i-1].is_free) {
                partitions[i-1].size += partitions[i].size;
                for (int j = i; j < num_partitions-1; j++) {
                    partitions[j] = partitions[j+1];
                }
                num_partitions--;
                i--;
            }
            if (i < num_partitions-1 && partitions[i+1].is_free) {
                partitions[i].size += partitions[i+1].size;
                for (int j = i+1; j < num_partitions-1; j++) {
                    partitions[j] = partitions[j+1];
                }
                num_partitions--;
            }
            break;
        }
    }
}

int main() {
    init_partitions();
    print_partitions();

    int addr1 = allocate_partition(20);
    printf("Allocated partition at address %d\n", addr1);
    print_partitions();

    int addr2 = allocate_partition(30);
    printf("Allocated partition at address %d\n", addr2);
    print_partitions();

    deallocate_partition(addr1);
    printf("Deallocated partition at address %d\n", addr1);
    print_partitions();

    int addr3 = allocate_partition(10);
    printf("Allocated partition at address %d\n", addr3);
    print_partitions();

    return 0;
}