Main.cc:4:20: error: expected initializer before ‘maxn’
int a[N],x,n,dp[N] maxn;
^~~~
Main.cc: In function ‘int main()’:
Main.cc:14:26: warning: suggest parentheses around ‘+’ inside ‘>>’ [-Wparentheses]
int mid=l+r>>1;
~^~
Main.cc:29:26: warning: suggest parentheses around ‘+’ inside ‘>>’ [-Wparentheses]
int mid=l+r>>1;
~^~