Compilare: main.cpp: In function 'int main()': main.cpp:11:11: warning: unused variable 'm' [-Wunused-variable] int n,m,i,j,k,l; ^ main.cpp:11:17: warning: unused variable 'k' [-Wunused-variable] int n,m,i,j,k,l; ^ main.cpp:11:19: warning: unused variable 'l' [-Wunused-variable] int n,m,i,j,k,l; ^ main.cpp:9:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("joctv.in","r",stdin); ^ main.cpp:10:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("joctv.out","w",stdout); ^ main.cpp:12:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ main.cpp:16:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&mat[i][j]); ^