Compilare: user.cpp: In function ‘int main()’: user.cpp:42:16: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if (i > 1 && !dw[i - 1][j]) ^ user.cpp:54:16: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if (i > 1 && !dw[i - 1][j]) ^ user.cpp:17:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("gravity.in", "r", stdin); ^ user.cpp:18:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("gravity.out", "w", stdout); ^ user.cpp:21:30: 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:25:23: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets (str + 1); ^ /tmp/ccwev4ji.o: In function `main': user.cpp:(.text.startup+0x88): warning: the `gets' function is dangerous and should not be used.