Compilare: user.cpp: In function ‘std::vector<Point> Build(std::vector<Point>)’: user.cpp:46:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<robot.size();i++) ^ user.cpp:49:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<oldObstacle.size();i++) ^ user.cpp:54:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<robot.size();i++){ ^ user.cpp:60:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<oldObstacle.size();i++) ^ user.cpp:65:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<temp.size()-1;i++) ^ user.cpp:69:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=2;i<newObstacle.size();i++){ ^ user.cpp: In function ‘bool InObstacle(Point, int)’: user.cpp:100:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1;i<obstacle[index].size();i++){ ^ user.cpp: In function ‘bool IsLine(Point, Point)’: user.cpp:114:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<obstacle[i].size();j++) ^ user.cpp:115:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=j+1;k<obstacle[i].size();k++) ^ user.cpp: In function ‘void BuildGraph()’: user.cpp:127:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=1;j<obstacle[i].size();j++){ ^ user.cpp: In function ‘void BellmanFord()’: user.cpp:150:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<g[node].size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:157:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("robot.in","r",stdin); ^ user.cpp:158:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("robot.out","w",stdout); ^ user.cpp:161:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:164:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&p.x,&p.y);