Compilare: user.cpp: In function ‘void add_solution(int, int, int)’: user.cpp:121:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < act.size(); i++) { ^ user.cpp:190:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < act.size(); i++) ^ user.cpp:116:9: warning: unused variable ‘i’ [-Wunused-variable] int i, j, target; ^ user.cpp:116:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, target; ^ user.cpp: In function ‘int main()’: user.cpp:248:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i + 2 < way.size(); i += 2) ^ user.cpp:198:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("santa.in","r",stdin); ^ user.cpp:199:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("santa.out","w",stdout); ^ user.cpp:201:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:203:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ user.cpp:207:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &S, &D, &Q); ^