C++ :

#include <stdio.h>
#include <stdlib.h>
/* memory指针记录当前可用地址的起始地址
   start_of_memory指针记录原始内存空间的起始地址
   end_of_memory指针记录原始内存空间的结束地址 */
char *memory, *start_of_memory, *end_of_memory;
int main() {
	char *alloc(int n);
	void tryfree(char *p);
	char *result;
	int m, n, i, new_block_size;
	scanf("%d %d", &m, &n);
	memory = (char *)malloc(m);
	start_of_memory = memory;
	end_of_memory = memory + m;
	for (i = 0;i < n;i++) {
		scanf("%d", &new_block_size);
		result = alloc(new_block_size);
		if (result == NULL)
			printf("%d ", 0);
		else
			printf("%d ", 1 + (result - start_of_memory));
	}
	printf("\n");
	return 0;
}
/* 内存分配函数 */
char *alloc(int n) {
	char *result = NULL;
	if (memory + n <= end_of_memory) {
		result = memory;
		memory += n;
	}
	return result;
}
/* 内存释放函数 */
void tryfree(char *p) {
	while (p < memory) {
		tryfree(p);
		p++;
	}
}