Compilare: main.cpp: In function 'int main()': main.cpp:27:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<strlen(s);i++) ~^~~~~~~~~~ main.cpp:29:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation] if(i%k==0) ^~ main.cpp:32:13: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if' if(ap[s[i]-'a']==false) ^~