Compilare: main.cpp: In function 'int main()': main.cpp:18:40: warning: unused variable 'cnt' [-Wunused-variable] int n , i , last = 0 , mxext = 0 , cnt , ans = 0 ; ^~~ main.cpp:16:45: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ( "pscpld.out" , "w" , stdout ) ; ^ main.cpp:20:34: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread ( str , 1 , NMAX , f ) ; ^