Compilare: user.cpp: In function ‘int check(int)’: user.cpp:21:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[node].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:69:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[node].size(); i++) ^ user.cpp:84:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < firstRow.size(); i++) ^ user.cpp:101:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[node].size(); i++) ^ user.cpp:115:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[node2].size(); i++) ^ user.cpp:133:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < firstRow.size(); i++) ^ user.cpp:138:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < firstRow.size(); i++) ^ user.cpp:163:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[node].size(); i++) ^ user.cpp:176:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[node].size(); i++) ^ user.cpp:190:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < firstRow.size(); i++) ^ user.cpp:202:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = 0; k < v[node].size(); k++) ^ user.cpp:228:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = 0; k <sol[i].size(); k++) ^