Compilare: user.cpp: In function ‘int main()’: user.cpp:59:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(lin = 1; lin <= n && sol.size() < initMatch; ++ lin) { ^ user.cpp:62:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(nPairs == initMatch - 1 - sol.size()) { ^ user.cpp:71:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(col = 1; col <= m && sol.size() < initMatch; ++ col) { ^ user.cpp:42:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("paznici.in", "r", stdin); ^ user.cpp:43:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("paznici.out", "w", stdout); ^ user.cpp:47:28: 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:50:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &ch); ^ user.cpp:48:5: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i = 1; i <= n; ++ i, scanf("\n")) ^