Compilare: user.cpp: In function ‘bool check(int, int)’: user.cpp:18:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=words[a].size();i++) ~^~~~~~~~~~~~~~~~~ user.cpp:19:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=1;j<=words[b].size();j++) ~^~~~~~~~~~~~~~~~~ user.cpp:26:84: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return (words[a].size()+words[b].size()-2*dp[words[a].size()][words[b].size()])<=k; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~