Compilare: main.cpp: In function 'int main()': main.cpp:49:61: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(s[j+1][k]==s[i+1][r-1]&&k<s[j+1].size()) ~^~~~~~~~~~~~~~ main.cpp:51:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(k==s[j+1].size()) ~^~~~~~~~~~~~~~~