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:71:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[node].size(); i++) ^ user.cpp:86:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < firstRow.size(); i++) ^ user.cpp:103:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[node].size(); i++) ^ user.cpp:117:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[node2].size(); i++) ^ user.cpp:135:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < firstRow.size(); i++) ^ user.cpp:140:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < firstRow.size(); i++) ^ user.cpp:165:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[node].size(); i++) ^ user.cpp:178:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[node].size(); i++) ^ user.cpp:192:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < firstRow.size(); i++) ^ user.cpp:204:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = 0; k < v[node].size(); k++) ^ user.cpp:230:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = 0; k <sol[i].size(); k++) ^