Compilare: main.cpp: In function 'int solve2(int, int, int)': main.cpp:22:13: warning: unused variable 'pn' [-Wunused-variable] int pn = NN; ^~ main.cpp: In function 'int main()': main.cpp:88:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("eq.in", "r", stdin); ^ main.cpp:89:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("eq.out", "w", stdout); ^