Compilare: user.cpp: In function ‘int main()’: user.cpp:30:69: warning: array subscript has type ‘char’ [-Wchar-subscripts] D[i][j]=min(D[i][j],D[i+1][t-1]+D[t+1][j]+C[v[i]][v[t]]); ^ user.cpp:30:75: warning: array subscript has type ‘char’ [-Wchar-subscripts] D[i][j]=min(D[i][j],D[i+1][t-1]+D[t+1][j]+C[v[i]][v[t]]); ^ user.cpp:12:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("redu.in","r",stdin); ^ user.cpp:13:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("redu.out","w",stdout); ^ user.cpp:15:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&N); ^ user.cpp:16:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",v+1); ^ user.cpp:20:45: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&C[i+'a'-1][j+'a'-1]); ^