#include <bits/stdc++.h>
using namespace std;
int n,m,v;
const int MAX=3*1e5+10;
int parent[MAX];
vector<int> graph[MAX];
int Find(int x)
{
if(parent[x]==x)return x;
else return parent[x]=Find(parent[x]);
}
void Unite(int x, int y)
{
x=Find(x);
y=Find(y);
parent[y]=x;
}
int det[MAX];
int dfs(int node)
{
if(det[node]!=-1)return det[node];
det[node]=1;
for(auto x:graph[node])
{
det[node]=max(det[node],dfs(x)+1);
}
return det[node];
}
int res[MAX];
void dfs2(int node, int step)
{
if(res[node]!=0)return res[node];
res[node]=step;
for(auto x:graph[node])
{
if(res[x]==0 && det[node]-1==det[x])
{
dfs2(x,step+1);
}
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin>>n>>m>>v;
for(int i=0; i<m; i++)parent[i]=i;
vector<pair<int,int> > op;
bool ind[m];
memset(res,0,sizeof(res));
memset(ind,false,sizeof(ind));
for(int i=0; i<v; i++)
{
int a;
cin>>a;
char c;
cin>>c;
int b;
cin>>b;
a--;
b--;
if(c=='=')Unite(a,b);
else op.push_back({a,b});
}
for(auto curr:op)
{
int a=Find(curr.first),b=Find(curr.second);
ind[b]=true;
graph[a].push_back(b);
}
memset(det,-1,sizeof(det));
for(int i=0; i<m; i++)
{
if(!ind[i] && graph[i].size()>0 && i==Find(i))
{
int tmp=dfs(i);
if(tmp==n)dfs2(i,1);
}
}
for(int i=0; i<m; i++)
{
int tmp=Find(i);
if(!res[tmp])cout<<"?"<<endl;
else
cout<<"K"<<res[tmp]<<endl;
}
return 0;
}
Compilation message
kovanice.cpp: In function 'void dfs2(int, int)':
kovanice.cpp:33:36: error: return-statement with a value, in function returning 'void' [-fpermissive]
33 | if(res[node]!=0)return res[node];
| ~~~~~~~~^
