Compilare: user.cpp: In function ‘int main()’: user.cpp:19:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[i].size();j++) ^ user.cpp:9:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] {freopen ("alpin.in","r",stdin); ^ user.cpp:10:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("alpin.out","w",stdout); ^ user.cpp:12:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:15:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] {scanf("%d",&ma[i][j]); ^ user.cpp:11:22: warning: ‘c’ may be used uninitialized in this function [-Wmaybe-uninitialized] int n,i,j,k,x,maxx,l,c; ^ user.cpp:11:20: warning: ‘l’ may be used uninitialized in this function [-Wmaybe-uninitialized] int n,i,j,k,x,maxx,l,c; ^