Compilare: user.cpp: In function ‘void upd(int, int, int)’: user.cpp:26:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while( i < A[a].size() && j < A[b].size() ){ ^ user.cpp:26:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while( i < A[a].size() && j < A[b].size() ){ ^ user.cpp:36:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(;i<A[a].size();i++) ^ user.cpp:38:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(;j<A[b].size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:76:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&n); ^ user.cpp:78:41: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&v[i].x,&v[i].y); ^ user.cpp:82:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&m); ^ user.cpp:85:43: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d%d%d",&a,&b,&a1,&b1); ^