Compilare: user.cpp: In function ‘int main()’: user.cpp:22:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( i = 0; i < strlen(q); ++i ) v[q[i]-'a']++; ^ user.cpp:25:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( i = 0; i < strlen(q); ++i ) r[q[i]-'a']++; ^ user.cpp:17:18: warning: unused variable ‘s’ [-Wunused-variable] int n, i, j, s, t, d, k, ma, ok; ^ user.cpp:17:21: warning: unused variable ‘t’ [-Wunused-variable] int n, i, j, s, t, d, k, ma, ok; ^ user.cpp:17:24: warning: unused variable ‘d’ [-Wunused-variable] int n, i, j, s, t, d, k, ma, ok; ^ user.cpp:17:27: warning: unused variable ‘k’ [-Wunused-variable] int n, i, j, s, t, d, k, ma, ok; ^ user.cpp:17:30: warning: unused variable ‘ma’ [-Wunused-variable] int n, i, j, s, t, d, k, ma, ok; ^ user.cpp:14:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("joben.in","r",stdin); ^ user.cpp:15:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("joben.out","w",stdout); ^ user.cpp:19:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%*c",&n); ^ user.cpp:21:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",q); ^ user.cpp:24:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",q); ^