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QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#215297#6329. Colorful Graphpengpeng_fudanWA 1052ms6564kbC++143.0kb2023-10-15 08:29:012023-10-15 08:29:01

Judging History

你现在查看的是最新测评结果

  • [2023-10-15 08:29:01]
  • 评测
  • 测评结果:WA
  • 用时:1052ms
  • 内存:6564kb
  • [2023-10-15 08:29:01]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;
using ull=unsigned long long;
using ll=long long;
const int N=7010,M=4*7010;
vector<int> ve[7010];
vector<int> re[7010];
int n,m;
int stk[N],sz[N],scc[N];
int dfn[N]; //时间戳,记录dfs序
int low[N];//追溯值
bool instk[N];
int cnt=0,tot=0,top=0;
void tarjan(int u){
    dfn[u]=low[u]=++tot;
    stk[++top]=u,instk[u]=true;
    for(auto i:ve[u]){
        if(!dfn[i]){
            tarjan(i);
            low[u]=min(low[u],low[i]);
        }
        else if(instk[i])   low[u]=min(low[u],dfn[i]);
    }
    if(dfn[u]==low[u]){
        ++cnt;
        int y;
        do{
            y=stk[top--];
            instk[y]=false;
            scc[y]=cnt;
            sz[cnt]++;
        }while(y!=u);
    }
}
const ll INF=1e18;
struct edge{int v;ll w,pre_w,nxt;}edge[2*M];
int head[2*N],cur[2*N],dep[2*N];
int ctz=1,st,ed;
int pot_sum;
void add(int u,int v,ll w){
    edge[++ctz]={v,w,w,head[u]};
    head[u]=ctz;
    edge[++ctz]={u,0,0,head[v]};
    head[v]=ctz;    
}
bool bfs(){
    copy(head,head+pot_sum+1,cur);
    fill(dep,dep+pot_sum+1,-1);
    queue<int> qe;
    dep[st]=0;qe.push(st);
    while(!qe.empty()){
        int t=qe.front();qe.pop();
        for(int i=head[t];i;i=edge[i].nxt){
            int v=edge[i].v;ll w=edge[i].w;
            if(w>0&&dep[v]==-1){
                dep[v]=dep[t]+1;
                qe.push(v);
            }
        }
    }
    return dep[ed]!=-1;
}
ll dfs(int u=st,ll flow=INF){
    ll rem=flow;
    if(u==ed)   return flow;
    for(int i=cur[u];i&&flow;i=edge[i].nxt){
        cur[u]=i;
        int v=edge[i].v;ll w=edge[i].w;
        if(w>0&&dep[v]==dep[u]+1){
            ll t=dfs(v,min(w,rem));
            rem-=t;
            edge[i].w-=t;
            edge[i^1].w+=t;
        } 
    }
    return flow-rem;
}
ll dinic(){
    ll ans=0;
    while(bfs())    ans+=dfs();
    return ans;
}
int col[N];
int c=0;
int color(int u){
    for(int i=head[u];i;i=edge[i].nxt){
        int v=edge[i].v;ll w=edge[i].pre_w-edge[i].w;
        if(v!=st&&v!=ed&&w>0){
            int t=color(v-cnt);
            edge[i].w++;
            col[u]=t;
            return t;
        }
    } 
    if(!col[u]) col[u]=++c;
    return col[u];  
}
void solve() {
    cin>>n>>m;
    int u,v;
    for(int i=1;i<=m;i++){
        cin>>u>>v;
        ve[u].push_back(v);
    } 
    for(int i=1;i<=n;i++){
        if(!dfn[i]) tarjan(i);
    } 
    st=0,ed=2*cnt+1;
    for(int i=1;i<=cnt;i++){add(0,i,1),add(i+cnt,ed,1),add(i+cnt,i,INF);}
    for(int i=1;i<=n;i++){
        for(auto j:ve[i]){
            if(scc[j]!=scc[i])  add(scc[i],scc[j]+cnt,INF);
        }
    }
    pot_sum=2*cnt+1;
    dinic();  
    for(int i=1;i<=cnt;i++){
        if(col[i])    continue;
        color(i);
    }
    for(int i=1;i<=n;i++)   cout<<col[scc[i]]<<' ';
    cout<<'\n';
}
int main() {
    ios::sync_with_stdio(0),cin.tie(0);
    int _ = 1;
    while(_--) solve();
    return 0;
}

Details

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Test #1:

score: 100
Accepted
time: 1ms
memory: 5692kb

input:

5 5
1 4
2 3
1 3
2 5
5 1

output:

2 2 2 1 2 

result:

ok AC

Test #2:

score: 0
Accepted
time: 1ms
memory: 3800kb

input:

5 7
1 2
2 1
4 3
5 1
5 4
4 1
4 5

output:

1 1 2 1 1 

result:

ok AC

Test #3:

score: 0
Accepted
time: 1ms
memory: 3848kb

input:

8 6
6 1
3 4
3 6
2 3
4 1
6 4

output:

1 1 1 1 2 1 3 4 

result:

ok AC

Test #4:

score: -100
Wrong Answer
time: 1052ms
memory: 6564kb

input:

7000 6999
4365 4296
2980 3141
6820 4995
4781 24
2416 5844
2940 2675
3293 2163
3853 5356
262 6706
1985 1497
5241 3803
353 1624
5838 4708
5452 3019
2029 6161
3849 4219
1095 1453
4268 4567
1184 1857
2911 3977
1662 2751
6353 6496
2002 6628
1407 4623
425 1331
4445 4277
1259 3165
4994 1044
2756 5788
5496 ...

output:

447 107 414 203 1 173 97 377 655 1505 1 1 97 1 232 57 516 30 702 25 498 585 1 253 102 29 29 1 334 28 1171 566 28 27 385 385 286 27 1 26 1525 614 26 534 25 687 25 1 24 24 879 23 1292 1 122 187 1 23 1031 22 575 1 1 1 158 22 1 1 243 21 21 710 21 981 20 1179 1 570 932 1 1 1 427 443 1 451 610 751 603 1 3...

result:

wrong answer 13 and 7 are not connected