Compilare: user.cpp: In function ‘int main()’: user.cpp:32:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < sol.size(); ++i) ^ user.cpp:14:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("swaps2.in", "r", stdin); ^ user.cpp:15:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("swaps2.out", "w", stdout); ^ user.cpp:17:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &n); ^ user.cpp:19:49: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s + 1), n = strlen(s + 1), k = n, j = 1; ^ /tmp/ccToPUCf.o: In function `main': user.cpp:(.text.startup+0x6a): warning: the `gets' function is dangerous and should not be used.