Compilare: user.cpp: In function ‘int main()’: user.cpp:94:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < ls[x].size(); j++) ^ user.cpp:100:48: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (w = 0; w < ls[y].size(); w++) { ^ user.cpp:144:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < ls[ymax].size(); j++) ^ user.cpp: In function ‘bool dfs(int, int)’: user.cpp:60:1: warning: control reaches end of non-void function [-Wreturn-type] } ^