Compilare: main.cpp: In function 'int main()': main.cpp:18:24: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare] 18 | for(int i = 1;i<strlen(s);i++) | ~^~~~~~~~~~ main.cpp:22:29: warning: array subscript has type 'char' [-Wchar-subscripts] 22 | if(opviz[s[i]]==0) | ~~~^ main.cpp:25:30: warning: array subscript has type 'char' [-Wchar-subscripts] 25 | opviz[s[i]]=1; | ~~~^ main.cpp:27:23: warning: array subscript has type 'char' [-Wchar-subscripts] 27 | fr[s[i]]++; | ~~~^ main.cpp:31:54: warning: array subscript has type 'char' [-Wchar-subscripts] 31 | if(s[i]>='a' && s[i]<='z' && lviz[s[i]]==0) | ~~~^ main.cpp:33:29: warning: array subscript has type 'char' [-Wchar-subscripts] 33 | lviz[s[i]]=1; | ~~~^ main.cpp:48:43: warning: array subscript has type 'char' [-Wchar-subscripts] 48 | fprintf(g,"%d\n",nec * fr[op[0]]*fr[op[0]]); | ~~~~^ main.cpp:48:53: warning: array subscript has type 'char' [-Wchar-subscripts] 48 | fprintf(g,"%d\n",nec * fr[op[0]]*fr[op[0]]); | ~~~~^