Compilare: user.cpp: In function ‘int main()’: user.cpp:41:25: warning: format ‘%s’ expects argument of type ‘char*’, but argument 2 has type ‘char (*)[50001]’ [-Wformat=] scanf("%s%s", &a, &b); ^ user.cpp:41:25: warning: format ‘%s’ expects argument of type ‘char*’, but argument 3 has type ‘char (*)[50001]’ [-Wformat=] user.cpp:37:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "swap.in", "r", stdin ); ^ user.cpp:38:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "swap.out", "w", stdout ); ^ user.cpp:41:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s%s", &a, &b); ^