Compilare: main.cpp: In function 'int get_value(char*)': main.cpp:26:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < strlen(s); i++) ~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:40:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < strlen(sir); i++) ~~^~~~~~~~~~~~~ main.cpp:39:9: warning: unused variable 'M' [-Wunused-variable] int M=strlen(sir); ^