Compilare: user.cpp: In function ‘int joule(char*)’: user.cpp:10: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void modif(char*)’: user.cpp:31: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:42: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:45: warning: ignoring return value of ‘int system(const char*)’, declared with attribute warn_unused_result user.cpp:46: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:47: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result