Compilare: main.cpp: In function 'int main()': main.cpp:31:24: warning: array subscript has type 'char' [-Wchar-subscripts] ++fv[str[i]]; ^ main.cpp:13:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("strdup.in","r",stdin); ^ main.cpp:14:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("strdup.out","w",stdout); ^ main.cpp:15:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t); ^ main.cpp:21:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s",str); ^