Compilare: user.cpp: In function ‘bool Check(int)’: user.cpp:42:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(( vis[i].first <= v[nr].x && v[nr].y >= vis[i].first ) || ( v[nr].y <= vis[i].second && v[nr].x >=vis[i].first ) ) ^ user.cpp:42:53: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(( vis[i].first <= v[nr].x && v[nr].y >= vis[i].first ) || ( v[nr].y <= vis[i].second && v[nr].x >=vis[i].first ) ) ^ user.cpp:42:84: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(( vis[i].first <= v[nr].x && v[nr].y >= vis[i].first ) || ( v[nr].y <= vis[i].second && v[nr].x >=vis[i].first ) ) ^ user.cpp:42:111: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(( vis[i].first <= v[nr].x && v[nr].y >= vis[i].first ) || ( v[nr].y <= vis[i].second && v[nr].x >=vis[i].first ) ) ^ user.cpp:44:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if( ( v[i].x <= vis[i].second && v[i].y >= vis[i].second ) || ( v[nr].y >= vis[i].first && v[nr].x <= vis[i].first) ) ^ user.cpp:44:53: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if( ( v[i].x <= vis[i].second && v[i].y >= vis[i].second ) || ( v[nr].y >= vis[i].first && v[nr].x <= vis[i].first) ) ^ user.cpp:44:85: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if( ( v[i].x <= vis[i].second && v[i].y >= vis[i].second ) || ( v[nr].y >= vis[i].first && v[nr].x <= vis[i].first) ) ^ user.cpp:44:112: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if( ( v[i].x <= vis[i].second && v[i].y >= vis[i].second ) || ( v[nr].y >= vis[i].first && v[nr].x <= vis[i].first) ) ^ user.cpp: In function ‘int main()’: user.cpp:57:6: warning: unused variable ‘right’ [-Wunused-variable] int right = 0 , left = 0 ; ^ user.cpp:57:18: warning: unused variable ‘left’ [-Wunused-variable] int right = 0 , left = 0 ; ^