代码开头通用模板

代码开头通用模板

#include<bits/stdc++.h>
using namespace std;
#define maxn 2020
#define rep(i,l,r) for(register int i = l ; i <= r ; i++)
#define repd(i,r,l) for(register int i = r ; i >= l ; i--)
#define rvc(i,S) for(register int i = 0 ; i < (int)S.size() ; i++)
#define rvcd(i,S) for(register int i = ((int)S.size()) - 1 ; i >= 0 ; i--)
#define fore(i,x)for (register int i = head[x] ; i ; i = e[i].next)
#define forup(i,l,r) for (register int i = l ; i <= r ; i += lowbit(i))
#define fordown(i,id) for (register int i = id ; i ; i -= lowbit(i))
#define pb push_back
#define prev prev_
#define stack stack_
#define mp make_pair
#define fi first
#define se second
#define inf 1e18
#define lowbit(x) (x&(-x))
typedef long long ll;
typedef pair<int,int> pr;

const ll mod = 998244353;

inline ll power(ll x,ll y){
	if ( y < 0 ) return 1;
	ll res = 1;
	while ( y ){
		if ( y & 1 ) res = res * x % mod;
		x = x * x % mod;
		y >>= 1;
	}
	return res;
}