I heard a bare board, so start now to learn
5 kinds of operation given by the subject can be converted to a differential constraint
If greater than the positive side of even $ 1 $
Is less than $ 1 $ even reverse side
If it is equal to build two-way side
Another: to open $ long long $
code
1 #include <bits/stdc++.h> 2 using namespace std; 3 namespace gengyf{ 4 #define int long long 5 const int mod=1e9+7; 6 const int maxn=1e5+10; 7 inline int read(){ 8 int x=0,f=1; 9 char c=getchar(); 10 while(c<'0'||c>'9'){if(c=='-')f=-1;c=getchar();} 11 while(c>='0'&&c<='9'){x=(x*10)+c-'0';c=getchar();} 12 return x*f; 13 } 14 int n,m,ans; 15 struct edge{ 16 int to,nxt,w; 17 }e[maxn*2]; 18 int head[maxn],cnt,dis[maxn],vis[maxn],us[maxn]; 19 inline void add(int from,int to,int w){ 20 e[++cnt].to=to;e[cnt].nxt=head[from]; 21 e[cnt].w=w;head[from]=cnt; 22 } 23 queue<int>q; 24 bool spfa(){ 25 while(!q.empty()){ 26 int x=q.front();q.pop(); 27 vis[x]=0;us[x]=1; 28 for(int i=head[x];i;i=e[i].nxt){ 29 int y=e[i].to; 30 if(dis[x]+e[i].w>dis[y]){ 31 dis[y]=dis[x]+e[i].w; 32 us[i]++; 33 if(us[i]>=n)return 0; 34 if(!vis[y]){ 35 q.push(y);vis[y]=1; 36 } 37 } 38 } 39 } 40 return 1; 41 } 42 int main(){ 43 n=read();m=read(); 44 for(int i=1;i<=m;i++){ 45 int x,a,b; 46 x=read();a=read();b=read(); 47 if(x==1)add(a,b,0),add(b,a,0); 48 if(x==2)add(a,b,1); 49 if(x==3)add(b,a,0); 50 if(x==4)add(b,a,1); 51 if(x==5)add(a,b,0); 52 if(x%2==0&&a==b){ 53 printf("-1\n");return 0; 54 } 55 } 56 for(int i=1;i<=n;i++){ 57 dis[i]=1;us[i]=1;vis[i]=1; 58 q.push(i); 59 } 60 if(!spfa()){ 61 printf("-1\n");return 0; 62 } 63 for(int i=1;i<=n;i++){ 64 ans+=dis[i]; 65 } 66 printf("%lld\n",ans); 67 return 0; 68 } 69 } 70 signed main(){ 71 gengyf::main(); 72 return 0; 73 }