Compilare: main.cpp: In function 'int main()': main.cpp:13:23: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare] 13 | for (int i = 0; i <= strlen(a); i++) | ~~^~~~~~~~~~~~ main.cpp:16:29: warning: array subscript has type 'char' [-Wchar-subscripts] 16 | while (top>0 and st[top] < x and m>0) | ^~~ main.cpp:21:12: warning: array subscript has type 'char' [-Wchar-subscripts] 21 | st[++top] = a[i]; | ^~~~~