通讯录1.2

1.用mstrcpy mstrcmp 代替了strcpy strcmp

2.新增write file函数，在程序最后创建一个文件把通讯录写入

void writefile(node head){int i = 0;FILE * file = fopen("./Addr_List", "w");if(file == NULL){perror("open:");return;}while(head->next != NULL){fprintf(file, "%d\n", i);fwrite(head->data.name, sizeof(char), 15, file);fwrite(head->data.num, sizeof(char), 15, file);fwrite(head->data.address, sizeof(char), 15, file);fprintf(file,"\n");head = head->next;i++;}fprintf(file, "%d\n", i);fwrite(head->data.name, sizeof(char), 15, file);fwrite(head->data.num, sizeof(char), 15, file);fwrite(head->data.address, sizeof(char), 15, file);fprintf(file,"\n");fclose(file);return;}

char* mstrcpy(char a[], const char * str){int i = 0;while(*(str + i) != '\0'){a[i] = *(str + i);i++;}a[i] = *(str + i);return a;}int mstrcmp(const char a[], const char b[]){int i = 0;while(a[i] == b[i] && a[i] != '\0'){i++;}if(a[i] > b[i]){return 1;}else if(a[i] < b[i]){return -1;}return 0;}