Compilare: user.cpp: In function ‘void change(char*, char, char)’: user.cpp:10:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<strlen(a);i++) ^ user.cpp: In function ‘int main()’: user.cpp:30:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<strlen(a);i++) ^ user.cpp:31:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] apar[a[i]]++; ^ user.cpp:29:17: warning: unused variable ‘par’ [-Wunused-variable] int par=0,impar=0; ^ user.cpp:49:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<strlen(a);i++) ^ user.cpp:23:15: warning: variable ‘ok’ set but not used [-Wunused-but-set-variable] int x,ok,apar[150]={0},i,apar2[150]={0}; ^ user.cpp:23:34: warning: unused variable ‘apar2’ [-Wunused-variable] int x,ok,apar[150]={0},i,apar2[150]={0}; ^