Compilare: user.cpp: In function ‘int main()’: user.cpp:34:47: warning: right operand of comma operator has no effect [-Wunused-value] gets(S), v[i].x = S, v[i].y = i, v; ^ user.cpp:46:64: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (j < min(v[i].x.length(), v[i + 1].x.length()) && v[i].x.at(j) == v[i + 1].x.at(j)) ^ user.cpp:7:26: warning: integer overflow in expression [-Woverflow] #define INF ((1 << 31) - 1) ^ user.cpp:70:29: note: in expansion of macro ‘INF’ start = minim = INF; ^ user.cpp:7:26: warning: integer overflow in expression [-Woverflow] #define INF ((1 << 31) - 1) ^ user.cpp:71:23: note: in expansion of macro ‘INF’ finish = -INF; ^ user.cpp:28:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ratina.in","r",stdin); ^ user.cpp:29:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ratina.out","w",stdout); ^ user.cpp:31:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n", &N, &M); ^ user.cpp:34:47: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(S), v[i].x = S, v[i].y = i, v; ^ user.cpp:68:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &nr); ^ user.cpp:75:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &X); ^ /tmp/cc5hTSQl.o: In function `main': user.cpp:(.text.startup+0x8a): warning: the `gets' function is dangerous and should not be used.