Compilare: user.cpp: In function ‘int main()’: user.cpp:40:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < d[i].size(); j++) { ^ user.cpp:22:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("copsamica.in", "r", stdin); ^ user.cpp:23:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("copsamica.out", "w", stdout); ^ user.cpp:28:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (scanf("%d", &testCase); testCase > 0; testCase--) { ^ user.cpp:29:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:34:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^