Compilare: user.cpp: In function ‘int main()’: user.cpp:80:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("danger.in", "r", stdin); ^ user.cpp:81:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("danger.out", "w", stdout); ^ user.cpp:83:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:94:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v[i][j]); ^ user.cpp: In function ‘int solve(int)’: user.cpp:59:25: warning: ‘y’ may be used uninitialized in this function [-Wmaybe-uninitialized] sol[x][j]=v[x][y]; ^ user.cpp:59:14: warning: ‘x’ may be used uninitialized in this function [-Wmaybe-uninitialized] sol[x][j]=v[x][y]; ^