Compilare: user.cpp: In function ‘int main()’: user.cpp:23:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( int i = 0; i < strlen(a) && sum <= w; sum += l[a[i]], i++ ); ~~^~~~~~~~~~~ user.cpp:23:58: warning: array subscript has type ‘char’ [-Wchar-subscripts] for( int i = 0; i < strlen(a) && sum <= w; sum += l[a[i]], i++ ); ^ user.cpp:29:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int sum = 0, i = 0; i < strlen(a) ; i++) ~~^~~~~~~~~~~ user.cpp:31:18: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(sum + l[a[i]] <= w - 3) ^ user.cpp:34:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] sum += l[a[i]]; ^ user.cpp:20:6: warning: unused variable ‘i’ [-Wunused-variable] int i = -1; ^ user.cpp:21:6: warning: unused variable ‘s’ [-Wunused-variable] int s = 0; ^