Compilare: main.cpp: In function 'int main()': main.cpp:34:25: warning: unused variable 'new_key' [-Wunused-variable] int n , S , i , j , new_key; ^~~~~~~ main.cpp:32:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("loto.in" , "r" , stdin); ^ main.cpp:33:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("loto.out" , "w" , stdout); ^ main.cpp:35:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d" , &n , &S); ^ main.cpp:37:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &v[i]); ^