Compilare: main.cpp: In function 'int main()': main.cpp:16:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0 ; j < v[i - 1].size() && j < v[i].size() && v[i][j] == v[i - 1][j] ; ++ j , -- cnt); ~~^~~~~~~~~~~~~~~~~ main.cpp:16:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0 ; j < v[i - 1].size() && j < v[i].size() && v[i][j] == v[i - 1][j] ; ++ j , -- cnt); ~~^~~~~~~~~~~~~ main.cpp:9:18: warning: unused variable 'lmax' [-Wunused-variable] int n, i, j, lmax, cnt, ok; ^~~~ main.cpp:9:29: warning: unused variable 'ok' [-Wunused-variable] int n, i, j, lmax, cnt, ok; ^~