Compilare: user.cpp: In function ‘int main()’: user.cpp:8:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("citylog.in","r",stdin); ^ user.cpp:9:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("citylog.out","w",stdout); ^ user.cpp:10:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:15:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&tip,&a,&b); ^ user.cpp:21:63: warning: iteration 8u invokes undefined behavior [-Waggressive-loop-optimizations] for(int j=1;j<=17;j++) dp[a][j]=dp[dp[a][j-1]][j-1]; ^ user.cpp:21:13: note: containing loop for(int j=1;j<=17;j++) dp[a][j]=dp[dp[a][j-1]][j-1]; ^