Compilare: user.cpp: In function ‘int Polygon_Area(std::vector<std::pair<int, int> >&)’: user.cpp:58:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<V.size(); i++) ^ user.cpp:59:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] ANS+=V[i].x*V[(i+1<V.size()?i+1:0)].y-V[i].x*V[(i>0?i-1:V.size()-1)].y; ^ user.cpp: In function ‘int PInside_Area(PI, std::vector<std::pair<int, int> >&)’: user.cpp:68:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<V.size(); i++) ^ user.cpp:69:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] ANS+=Area(V[i], V[(i<V.size()-1?i+1:0)], P); ^ user.cpp: In function ‘void Convex_Hull(std::vector<std::pair<int, int> >&)’: user.cpp:84:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=1; i<V.size(); i++) ^ user.cpp:98:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<ST.size()-1; i++) ^ user.cpp: In function ‘bool IntersectPolygon(PI, PI, std::vector<std::pair<int, int> >&)’: user.cpp:124:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<V.size()-1; i++) ^ user.cpp:130:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<V.size(); i++) ^ user.cpp:132:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] int nx=(i<V.size()-1?i+1:0); ^ user.cpp:147:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<V.size(); i++) ^ user.cpp:148:56: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (IntersectSegment(A, B, V[i], V[(i+1<V.size()?i+1:0)])) ^ user.cpp: In function ‘void Expand_Obstacles()’: user.cpp:161:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<Obstacles.size(); i++) ^ user.cpp:166:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k=0; k<Robot.size(); k++) ^ user.cpp: In function ‘void Calculate_Finish()’: user.cpp:176:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=1; i<Robot.size(); i++) ^ user.cpp: In function ‘double GetDist(PI, PI)’: user.cpp:186:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]