Compilare: main.cpp: In function 'int main()': main.cpp:80:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i < x.second.size (); i++) ~~^~~~~~~~~~~~~~~~~~ main.cpp:88:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i < x.second.size (); i++) ~~^~~~~~~~~~~~~~~~~~ main.cpp:57:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("zc.in", "r", stdin); ^ main.cpp:58:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ("zc.out", "w", stdout); ^ main.cpp:59:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &n, &m); ^ main.cpp:61:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &x, &y); ^ main.cpp:95:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ("\n"); ^ main.cpp:97:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ("%c %d\n", &c, &val); ^