Compilare: user.cpp: In function ‘int main()’: user.cpp:56:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; k && i < e[1].size(); i++) ^ user.cpp:32:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("karb.in", "r", stdin); ^ user.cpp:33:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("karb.out", "w", stdout); ^ user.cpp:35:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &n, &m, &k); ^ user.cpp:37:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &x, &y, &c); ^