Compilare: user.cpp: In function ‘int main()’: user.cpp:125:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = wl; j < z.size() - 1; j++) ^ user.cpp:152:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < mrs.size() - 1; i++) ^ user.cpp:172:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < r.size(); j++) ^ user.cpp:151:9: warning: variable ‘id’ set but not used [-Wunused-but-set-variable] int id = 0; ^ user.cpp:67:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("elmer.in", "r", stdin); ^ user.cpp:68:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("elmer.out", "w", stdout); ^ user.cpp:71:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:75:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ user.cpp:79:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &M); ^ user.cpp:83:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^