Compilare: main.cpp: In function 'int main()': main.cpp:13:12: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] s[n+1]=NULL; ^~~~ main.cpp:35:24: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] fis[w]=NULL; ^~~~ main.cpp:26:9: warning: this 'else' clause does not guard... [-Wmisleading-indentation] else ^~~~ main.cpp:47:13: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'else' if(s[i]==')') ^~