Compilare: user.cpp: In function ‘int main()’: user.cpp:59:18: warning: NULL used in arithmetic [-Wpointer-arith] while(ch[i]!=NULL) ^ user.cpp:87:22: warning: NULL used in arithmetic [-Wpointer-arith] while(ch[j]!=NULL) ^ user.cpp:48:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d %d", &n, &m); ^ user.cpp:56:26: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(ch, 100005, in); ^ user.cpp:57:26: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(ch, 100005, in); ^ user.cpp:85:28: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(ch, 1005, in); ^