Main.cc: In function 'int main()': Main.cc:528:5: error: 'arr' was not declared in this scope a[arr[i]]++; ^ Main.cc:530:8: error: 'o' was not declared in this scope int m=o; ^ Main.cc:533:9: warning: array subscript has type 'char' [-Wchar-subscripts] if(a[c]>m){ ^ Main.cc:534:9: warning: array subscript has type 'char' [-Wchar-subscripts] m=a[c]; ^