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QOJ
ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#762132 | #2517. Critical Structures | SanguineChameleon# | AC ✓ | 35ms | 30040kb | C++20 | 2.8kb | 2024-11-19 13:52:17 | 2024-11-19 13:52:19 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define f first
#define s second
#define mp make_pair
#define eb emplace_back
#define pb push_back
typedef pair<int,int> pii;
const int mxn = 1005;
const int mxm = 1000005;
vector<pii> adjl[mxn];
int cols[mxm],nex_col;
int cnt[mxm], max_cnt;
int dep[mxn];
int be[mxn];//among all the descendants and ourselves, what's the shallowest back edge
int art_pts,bridges;
void dfs(int nd, int p=-1){
be[nd]=dep[nd];
int conns=dep[nd];
int children_cnt=0;
int maxi=0;
for(pii nex:adjl[nd]){
int x=nex.f;//the node
// int id = nex.s;//edge id
if(x==p)continue;
if(dep[x]!=-1){
//back edge
conns=min(conns, dep[x]);
continue;
}
dep[x]=dep[nd]+1;
dfs(x,nd);
children_cnt++;
be[nd] = min(be[nd], be[x]);
maxi = max(maxi, be[x]);//check if there exists child that cannot reach top
}
//check art pt (with parent)
if((p==-1 && children_cnt>=2) || (p!=-1 && maxi>=dep[nd])){
// cout<<"art pt: "<<nd<<'\n';
art_pts++;
}
if(be[nd]>=dep[nd]){
if(p!=-1 && conns >= dep[nd]){
// cout<<"bridge: "<<nd<<'\n';
bridges++;
}
}
be[nd] = min(be[nd], conns);
// cout<<nd<<' '<<dep[nd]<<' '<<be[nd]<<'\n';
}
void dfs2(int nd, int pc=1,int p=-1){//edge colouring
for(pii nex:adjl[nd]){
int x=nex.f;int id = nex.s;
if(dep[x]==dep[nd]+1){//child
if(be[x]<dep[nd]){
cols[id]=pc;
}else cols[id]=nex_col++;
cnt[cols[id]]++;
max_cnt = max(max_cnt, cnt[cols[id]]);
dfs2(x,cols[id], nd);
}else if(dep[x]!=dep[nd]-1 && dep[x]<dep[nd]){//back edge
cols[id]=pc;
cnt[cols[id]]++;
max_cnt = max(max_cnt, cnt[cols[id]]);
}
}
}
void solve(){
int n,m;
cin>>n>>m;
//init
for(int i=1;i<=n;i++){
adjl[i].clear();
dep[i]=-1;
}
bridges=art_pts=0;nex_col=2;
for(int i=1;i<=m;i++){
cnt[i]=0;
}max_cnt=0;
for(int i=0;i<m;i++){
int a,b;
cin>>a>>b;
adjl[a].eb(b,i);
adjl[b].eb(a,i);
}
dep[1]=1;
dfs(1);
dfs2(1);
int p= nex_col-1;
int q= max_cnt;
if(cnt[1]==0)p--;
int g = __gcd(p,q);
// g=1;
// for(int i=0;i<m;i++)cout<<cols[i]<<' ';cout<<'\n';
cout<<art_pts<<' '<<bridges<<' '<<p/g<<' '<<q/g<<'\n';
}
int32_t main() {
ios_base::sync_with_stdio(false);cin.tie(0);
int tc;
cin>>tc;
while(tc--){
solve();
}
}
/*
1
6 6
1 2
2 3
3 4
4 5
5 6
6 1
*/
详细
Test #1:
score: 100
Accepted
time: 1ms
memory: 5656kb
input:
1 6 6 1 2 2 3 3 4 4 5 5 6 6 1
output:
0 0 1 6
result:
ok single line: '0 0 1 6'
Test #2:
score: 0
Accepted
time: 1ms
memory: 5640kb
input:
1 6 7 1 2 2 3 3 1 4 5 5 6 6 4 1 4
output:
2 1 1 1
result:
ok single line: '2 1 1 1'
Test #3:
score: 0
Accepted
time: 35ms
memory: 30040kb
input:
10 6 6 1 2 2 3 3 4 4 5 5 6 6 1 5 4 1 2 2 3 3 4 4 5 5 7 1 2 1 3 3 4 4 5 5 3 1 4 1 5 13 16 1 2 1 6 1 3 1 7 3 7 4 6 4 5 5 6 5 7 7 8 8 9 7 10 10 11 12 13 10 12 10 13 10 11 1 2 2 3 2 4 3 5 4 5 4 6 6 7 7 8 6 8 8 9 8 10 3 3 1 2 2 3 3 1 44 66 1 5 1 12 1 33 2 27 2 31 2 32 2 35 2 37 2 40 3 6 3 30 3 44 4 20 4 ...
output:
0 0 1 6 3 4 4 1 1 1 1 3 4 5 7 8 4 4 3 2 0 0 1 3 8 9 10 57 0 0 1 499500 2 2 3 1777 108 112 113 1531
result:
ok 10 lines