Compilare: user.cpp: In function ‘double calculate_sum(int, int*, int)’: user.cpp:59:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 0; i < A[x].size(); i++ ) ^ user.cpp: In function ‘int main()’: user.cpp:99:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 1; i < Nodes.size()-1; i++) ^ user.cpp:121:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 0; i < Nodes.size()-1; i++) ^ user.cpp:138:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 0; i < Nodes.size()-1; i++) ^ user.cpp:154:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 0; i < Nodes.size()-1; i++) ^ user.cpp:170:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 0; i < Nodes.size()-1; i++) ^