记录一下为数不多的网络流

#pragma GCC optimize(3,"Ofast","inline")
#include<bits/stdc++.h>
#include <execution>
using namespace std;
using i64 = long long;
using i128 = __int128;template <typename T>struct MCFgraph{struct edge{int v;T c,f;edge(int v,T c,T f):v(v),c(c),f(f){}};  const int n;vector<edge> e;vector<vector<int>> g;vector<i64> h,dis;vector<int> pre;bool dij(int s,int t){dis.assign(n,numeric_limits<i64>::max());pre.assign(n,-1);priority_queue<pair<i64,int>,vector<pair<i64,int>>,greater<pair<i64,int>>> q;dis[s]=0;q.emplace(0,s);while(!q.empty()){i64 d = q.top().first;int u = q.top().second;q.pop();for(int i:g[u]){int v = e[i].v;T c = e[i].c;T f = e[i].f;if(c>0&&dis[v]>d+h[u]-h[v]+f){dis[v] = d+h[u]-h[v]+f;pre[v]=i;q.emplace(dis[v],v);}}}return dis[t]!=numeric_limits<i64>::max();}MCFgraph(int n):n(n),g(n){}void addedge(int u,int v,T c,T f){g[u].push_back(e.size());e.emplace_back(v,c,f);g[v].push_back(e.size());e.emplace_back(u,0,-f);}pair<T,i64> flow(int s,int t){T flow = 0;i64 cost = 0;h.assign(n,0);while(dij(s,t)){for(int i = 0;i<n;++i) h[i]+=dis[i];T aug = numeric_limits<i64> ::max();for(int i = t;i!=s;i = e[pre[i]^1].v) aug= min(aug,e[pre[i]].c);for(int i = t;i!=s;i = e[pre[i]^1].v){e[pre[i]].c-=aug;e[pre[i]^1].c+=aug;}flow+=aug;cost+=i64(aug*h[t]);}return make_pair(flow,cost);}
};
using mcf = MCFgraph<i64>;void solve(){int n;cin>>n;mcf g(4*n+10);//0,4*n+1 (i-1)*3+1+2+3int id=3*n+1;constexpr i64 inf = 1e18;vector<int> a(n+1);for(int i = 1;i<=n;++i){int op;cin>>op;if(i+1<=n){g.addedge((i-1)*3+1,i*3+1,inf,0);g.addedge((i-1)*3+2,i*3+2,inf,0);g.addedge((i-1)*3+3,i*3+3,inf,0);}if(op==1){cin>>a[i];g.addedge(0,id,1,0);g.addedge(id,(i-1)*3+1,1,1);g.addedge(id,(i-1)*3+2,1,(a[i]+9)/10);g.addedge(id,(i-1)*3+3,1,0);g.addedge(id,4*n+1,1,a[i]);id++;//更新id}else{g.addedge((i-1)*3+1,4*n+1,1,0);g.addedge((i-1)*3+2,4*n+1,1,0);g.addedge((i-1)*3+3,4*n+1,1,0);}}i64 sum = reduce(std::execution::par,a.begin()+1,a.end(),0);cout<<sum-g.flow(0,4*n+1).second<<"\n";
}signed main(){ios::sync_with_stdio(0);cin.tie(0);int t=1;cin>>t;while(t--) solve();return 0;
}