code——tmp

#include<queue> 
#include<vector> 
#include<cstdio> 
#include<algorithm> 
#define pc putchar
#define gc getchar() 
#define rep(a,b,c) for(int a = b;a <= c;++ a) 
#define per(a,b,c) for(int a = b;a >= c;-- a) 
inline int read() { 
	int x = 0,f = 1; 
	char c = gc; 
	while(c < '0' || c > '9') c = gc; 
	while(c <= '9' && c >= '0') x = x * 10 + c - '0',c = gc; 
	return x * f ;
} 
void print(int x) { 
	if(x < 0) { 
		pc('-'); x = -x; 
	} 
	if(x >= 10) print(x / 10); 
	pc(x % 10 + '0');  	
} 
const int maxn = 100007; 
int a[maxn << 1]; 
struct node {
	int v,next; 
	bool cut; 
} edge[maxn << 1]; 
int head[maxn],num = 1; 
inline void add_edge(int u,int v) {
 	edge[++ num].v = v; edge[num].next = head[u];head[u] = num; 
	e[num].cut = 0 ;
} 
bool vis[maxn]; 
void tarjan(int x,int fa) { 
	low[x] = dfn[x] = ++ index; 
	stk[++ top] = x; 
	vis[x] = 1; 
	for(int i = head[x];i;i = edge[i].next) { 
		int v = edge[i].v; 
		if(v == fa) continue; 
		if(!dfn[v]) { 
			tarjan(v,x); 
			low[x] = std::min(low[x],low[v]); 
			if(low[v] > dfn[u]) { 
				bridge ++; 
				edge[i].cut = true; 
				edge[i ^ 1].cut = true; 
			} 
		} 
		else if(vis[v] && low[u] > dfn[v]) 
			low[u] = dfn[v];  
	} 
	if(dfn[x] == low[x]) { 
		 
	
}  
void solve() { 
	n = read();m = read(); 
	for(int u,v,i = 1;i <= m;++ i) { 
		u = read(),v = read(); 
		add_edge(u,v); 
		add_edge(v,u); 
	} 
	memset(dfn,0,sizeof dfn); 
	top = block = index = bridge = 0; 
	for(int i = 1;i <= n;++ i) if(!dfn[i]) tarjan(i,i);  
	
} 
int main() { 	
	int t = read(); 
	for(int i = 1;i <= t;++ i) { 
		memset(head,0,szieof head); num = 0; 
		solve(); 
	}  
}