/in/foo.cc:3:1: error: 'ypedef' does not name a type
 ypedef double db;
 ^~~~~~
/in/foo.cc:7:1: error: 'db' does not name a type
 db sum[maxn],dp[maxn];
 ^~
/in/foo.cc:9:8: error: 'db' does not name a type
 inline db a(int i){return sum[i]+i;}
        ^~
/in/foo.cc:10:8: error: 'db' does not name a type
 inline db b(int i){return a(i)+L+1;}
        ^~
/in/foo.cc:11:8: error: 'db' does not name a type
 inline db X(int i){return b(i);}
        ^~
/in/foo.cc:12:8: error: 'db' does not name a type
 inline db Y(int i){return dp[i]+b(i)*b(i);}
        ^~
/in/foo.cc:13:8: error: 'db' does not name a type
 inline db slope(int i,int j){return (Y(i)-Y(j))/(X(i)-X(j));}
        ^~
/in/foo.cc: In function 'int main()':
/in/foo.cc:18:22: error: 'sum' was not declared in this scope
         scanf("%lf",&sum[i]);
                      ^~~
/in/foo.cc:23:49: error: 'slope' was not declared in this scope
         while(head<tail&&slope(Q[head],Q[head+1])<2*a(i)) ++head;
                                                 ^
/in/foo.cc:23:56: error: 'a' was not declared in this scope
         while(head<tail&&slope(Q[head],Q[head+1])<2*a(i)) ++head;
                                                        ^
/in/foo.cc:24:9: error: 'dp' was not declared in this scope
         dp[i]=dp[Q[head]]+(a(i)-b(Q[head]))*(a(i)-b(Q[head]));
         ^~
/in/foo.cc:24:31: error: 'a' was not declared in this scope
         dp[i]=dp[Q[head]]+(a(i)-b(Q[head]))*(a(i)-b(Q[head]));
                               ^
/in/foo.cc:24:42: error: 'b' was not declared in this scope
         dp[i]=dp[Q[head]]+(a(i)-b(Q[head]))*(a(i)-b(Q[head]));
                                          ^
/in/foo.cc:25:43: error: 'slope' was not declared in this scope
         while(head<tail&&slope(i,Q[tail-1])<slope(Q[tail-1],Q[tail])) --tail;
                                           ^
/in/foo.cc:28:25: error: 'dp' was not declared in this scope
     printf("%lld\n",(LL)dp[n]);
                         ^~