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| #include <bits/stdc++.h>
#pragma optimization_level 3
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math,O3")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimization ("unroll-loops")
#define MAX_N 707
#define ll long long
#define pll pair<ll, ll>
#define vpll vector<pll>
#define vll vector<ll>
#define vall3 vector<array<ll,3>>
#define vs vector<string>
#define vvll vector<vll>
#define all(a) begin(a), end(a)
using namespace std;
ll n;
unordered_map<ll,ll> adj[MAX_N];
ll path[MAX_N];
bool bfs(ll u, ll v) {
memset(path, 0, sizeof path);
queue<ll> q;
q.push(u);
while(!q.empty() and !path[v]) {
auto n = q.front(); q.pop();
for(auto& [m, w] : adj[n]) {
if(!w or path[m]) continue;
path[m] = n;
q.push(m);
}
}
return path[v] != 0;
}
ll solve(vall3& edges, ll u, ll v) {
for(auto& [u, v, w] : edges) {
adj[u][v] += w;
adj[v][u] += 0;
}
while(bfs(u,v)) {
ll vv = v, mi = INT_MAX;
while(vv != u) {
auto uu = path[vv];
mi = min(mi, adj[uu][vv]);
vv = uu;
}
vv = v;
while(vv != u) {
auto uu = path[vv];
adj[uu][vv] -= mi;
adj[vv][uu] += mi;
vv = uu;
}
}
queue<ll> q;
unordered_set<ll> A;
q.push(u);
A.insert(u);
while(!q.empty()) {
ll n = q.front(); q.pop();
for(auto& [m, w] : adj[n]) {
if(!w or A.count(m)) continue;
A.insert(m);
q.push(m);
}
}
ll res = 0;
for(ll i = 1; i <= n; i++) {
if(A.count(i)) continue;
for(auto& [v, w] : adj[i]) {
if(!A.count(v)) continue;
res += w;
}
}
return res;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin>>n;
string u, v;
ll w, no = 1;
unordered_map<string, ll> idmp;
vall3 edges;
for(ll i = 1; i <= n; i++) {
cin>>u>>v>>w;
ll uid = idmp.count(u) ? idmp[u] : idmp[u] = no++;
ll vid = idmp.count(v) ? idmp[v] : idmp[v] = no++;
edges.push_back({uid,vid,w});
}
cout<<solve(edges, idmp["A"], idmp["Z"]);
return 0;
}
|
