rt。我写了一个函数，报错了。

#include <bits/stdc++.h>
#define int long long
#define fin(x) freopen (x,"r",stdin)
#define fout(x) freopen (x,"w",stdout)
#define reg(i,x,y) for (register int i=(x);i<=(y);++i)
#define Reg(i,x,y) for (register int i=(y);i>=(x);--i)
using namespace std;
int n,m;
struct edge{
	vector<int> a;
	inline int size () {return a.size ();}
	inline void push (int x) {a.push_back (x);}
	inline int operator[] (int i) {return a[i];}
	inline void sort () {sort (a.begin (),a.end ());}//这里
	edge () {a.resize (0);}
};
vector<edge> a (1);
inline int read (void) {int x=0,f=0;char ch=getchar ();while (!isdigit (ch)) {f|=(ch=='-');ch=getchar ();}while (isdigit (ch)) x=(x<<1)+(x<<3)+(ch^48),ch=getchar ();return f?-x:x;}
inline void write (int x) {if (x<0) putchar ('-'),x=-x;if (x>9) write (x/10);putchar (x%10|48);}
signed main ()
{
	n=read (),m=read ();
	a.resize (n+1);
	
	return 0;
}