Compilare: main.cpp: In function 'int main()': main.cpp:52:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(it=0;it<v.size();it++) ~~^~~~~~~~~ main.cpp:38:28: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d%d",&n,&m); ^ main.cpp:43:39: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d",&mat[i][j]); ^