Compilare: user.cpp: In function ‘int main()’: user.cpp:48:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] lastA[ch][i] = (A[i] == ch) ? i : lastA[ch][i - 1]; ^ user.cpp:48:55: warning: array subscript has type ‘char’ [-Wchar-subscripts] lastA[ch][i] = (A[i] == ch) ? i : lastA[ch][i - 1]; ^ user.cpp:51:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] lastB[ch][i] = (B[i] == ch) ? i : lastB[ch][i - 1]; ^ user.cpp:51:55: warning: array subscript has type ‘char’ [-Wchar-subscripts] lastB[ch][i] = (B[i] == ch) ? i : lastB[ch][i - 1]; ^ user.cpp:57:37: warning: array subscript has type ‘char’ [-Wchar-subscripts] int k = lastA[ch][i - 1]; ^ user.cpp:58:37: warning: array subscript has type ‘char’ [-Wchar-subscripts] int l = lastB[ch][i - 1]; ^ user.cpp:71:25: warning: array subscript has type ‘char’ [-Wchar-subscripts] int k = lastA[ch][N - 1]; ^ user.cpp:72:25: warning: array subscript has type ‘char’ [-Wchar-subscripts] int l = lastB[ch][M - 1]; ^ /tmp/ccLQVJfO.o: In function `main': user.cpp:(.text.startup+0x4e): warning: the `gets' function is dangerous and should not be used.