Compilare: main.cpp: In function 'int main()': main.cpp:22:15: warning: unused variable 'k' [-Wunused-variable] int n,i,j,k,sol; ^ main.cpp:22:17: warning: variable 'sol' set but not used [-Wunused-but-set-variable] int n,i,j,k,sol; ^~~ main.cpp:20:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("custi.in","r",stdin); ^ main.cpp:21:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("custi.out","w",stdout); ^ main.cpp:23:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ main.cpp:27:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&a[i][j]); ^