Compilare: main.cpp: In function 'int main()': main.cpp:29:58: warning: array subscript has type 'char' [-Wchar-subscripts] 29 | while(!st.empty() && a[i] < st.top() && f1[st.top()] > f2[st.top()]){ | ~~~~~~^~ main.cpp:29:73: warning: array subscript has type 'char' [-Wchar-subscripts] 29 | while(!st.empty() && a[i] < st.top() && f1[st.top()] > f2[st.top()]){ | ~~~~~~^~ main.cpp:30:22: warning: array subscript has type 'char' [-Wchar-subscripts] 30 | f2[st.top()]++; | ~~~~~~^~ main.cpp:33:18: warning: array subscript has type 'char' [-Wchar-subscripts] 33 | if(f2[a[i]]){ | ~~~^ main.cpp:35:19: warning: array subscript has type 'char' [-Wchar-subscripts] 35 | f2[a[i]]--; | ~~~^ main.cpp:37:15: warning: array subscript has type 'char' [-Wchar-subscripts] 37 | f1[a[i]]--; | ~~~^