Compilare: user.cpp: In function ‘int main()’: user.cpp:62:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<lst[i].size();j++){ ^ user.cpp:40:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("suma6.in", "r", stdin); ^ user.cpp:41:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("suma6.out", "w", stdout); ^ user.cpp:49:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &l, &r); ^