Compilare: user.cpp: In function ‘int main()’: user.cpp:61:28: warning: format ‘%d’ expects argument of type ‘int’, but argument 3 has type ‘long long int’ [-Wformat=] fprintf(fout, "%d", sum); ^ user.cpp:31:35: 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:35:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%c", &s[i]); ^