Compilare: main.cpp: In function 'int main()': main.cpp:15:25: warning: array subscript has type 'char' [-Wchar-subscripts] while(v[i]>st[top]&&k>0&&top>0) ^ main.cpp:17:15: warning: array subscript has type 'char' [-Wchar-subscripts] st[++top]=v[i]; ^ main.cpp:7:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("alibaba.in","r",stdin); ^ main.cpp:8:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("alibaba.out","w",stdout); ^