Compilare: main.cpp: In function 'int main()': main.cpp:54:13: warning: unused variable 'semn' [-Wunused-variable] int i,j,semn; ^~~~ main.cpp:55:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("snake.in","r",stdin); ^ main.cpp:56:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("snake.out","w",stdout); ^ main.cpp:57:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n,&m,&l); ^ main.cpp:61:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a[i][j]); ^