Compilare: user.cpp: In function ‘int solve()’: user.cpp:14:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0,j=0,t=0,k=1;i<v[0].size();) { ^ user.cpp:15:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i<v[0].size()&&v[0][i].first<=k) ^ user.cpp: In function ‘int main()’: user.cpp:46:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if ((p<v[i].size()&&v[i][p].first<v[j][q].first)||(q==v[j].size())) ^ user.cpp:46:89: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if ((p<v[i].size()&&v[i][p].first<v[j][q].first)||(q==v[j].size())) ^ user.cpp:30:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("carpetbomber.in","r",stdin); ^ user.cpp:31:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("carpetbomber.out","w",stdout); ^ user.cpp:32:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:34:44: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&t[i],&x[i],&y[i]); ^