Compilare: main.cpp: In function 'int main()': main.cpp:18:25: warning: unused variable 'x' [-Wunused-variable] int n , m , i , j , x ; ^ main.cpp:15:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ( "zoro.in" , "r" , stdin ) ; ^ main.cpp:16:43: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ( "zoro.out" , "w" , stdout ) ; ^ main.cpp:20:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d%d" , & n , & m ) ; ^ main.cpp:25:48: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d" , & mat [ i ] [ j ] ) ; ^