Compilare: main.cpp: In function 'bool ok(int)': main.cpp:19:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(s[i].size() < x) ~~~~~~~~~~~~^~~ main.cpp:22:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j + x <= s[i].size() ;j++) ~~~~~~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:45:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation] for(int i = 1; i <= n; i++) ^~~ main.cpp:48:9: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for' int l = 2; ^~~