Compilare: user.cpp: In function ‘int main()’: user.cpp:14:22: warning: unused variable ‘x’ [-Wunused-variable] int res, cntCol, x, i, j, cpy, lin1, lin2; ^ user.cpp:12:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fold.in", "r", stdin); ^ user.cpp:13:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fold.out", "w", stdout); ^ user.cpp:17:28: 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:19:17: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(ln); ^ /tmp/ccBEeO6N.o: In function `main': user.cpp:(.text.startup+0x9a): warning: the `gets' function is dangerous and should not be used.