Compilare: main.cpp: In function 'int main()': main.cpp:15:15: warning: unused variable 'sol' [-Wunused-variable] long long sol; ^~~ main.cpp:16:32: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d\n",&n,&l); ^ main.cpp:18:32: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fgets (s[i]+1,l+10,fin); ^ main.cpp:21:36: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d",&cst[i-1]); ^