Compilare: user.cpp: In function ‘void mutare(int)’: user.cpp:13:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=i+1;j<strlen(s);j++) ^ user.cpp: In function ‘int main()’: user.cpp:29:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=1;i<strlen(s)-1;i++) ^ user.cpp:61:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<strlen(s)-1) ^ user.cpp:20:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("charlie.in", "r", stdin); ^ user.cpp:21:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("charlie.out", "w", stdout); ^ user.cpp:23:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &p); ^ user.cpp:24:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s\n", s); ^