Compilare: user.cpp: In function ‘int main()’: user.cpp:32:75: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(dp[i][j]>dp[i+1][k-1]+dp[k+1][j]+c[s[i]-'a'+1][s[k]]-'a'+1)dp[i][j]=dp[i+1][k-1]+dp[k+1][j]+c[s[i]-'a'+1][s[k]-'a'+1]; ^ 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:14:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&n); ^ user.cpp:15:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s\n",s+1); ^ user.cpp:18:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ", &c[i][j]); ^