Compilare: user.cpp: In function ‘int main()’: user.cpp:78:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<strlen(s); ++j) ^ user.cpp:72:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d\n", &n, &m); ^ user.cpp:74:27: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s, 150, fin); ^