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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 vall3 vector<array<ll,3>>
#define vll vector<ll>
#define vs vector<string>
#define usll unordered_set<ll>
#define vvs vector<vs>
#define vvll vector<vll>
#define all(a) begin(a), end(a)
using namespace std;
ll source = 606, sink = 607, bridge = 608;
ll path[MAX_N], cost[MAX_N][MAX_N], flo[MAX_N][MAX_N], cap[MAX_N][MAX_N];
vll adj[MAX_N];
bool bfs(ll u, ll v) {
bool inc[MAX_N];
vll w(MAX_N, 987654321);
memset(inc, 0, sizeof inc);
memset(path, 0, sizeof path);
w[u] = 0;
inc[u] = true;
queue<ll> q;
q.push(u);
while(!q.empty()) {
auto n = q.front(); q.pop();
inc[n] = false;
for(auto& m : adj[n]) {
if(cap[n][m] - flo[n][m] > 0 and w[n] + cost[n][m] < w[m]) {
w[m] = w[n] + cost[n][m];
path[m] = n;
if(!inc[m]) {
inc[m] = true;
q.push(m);
}
}
}
}
return path[v] != 0;
}
ll solve() {
ll res = 0;
while(bfs(source, sink)) {
ll v = sink, mi = INT_MAX;
while(source != v) {
ll u = path[v];
mi = min(mi, cap[u][v] - flo[u][v]);
v = u;
}
v = sink;
while(source != v) {
ll u = path[v];
res += mi * cost[u][v];
flo[u][v] += mi;
flo[v][u] -= mi;
v = u;
}
}
return -res;
}
void connect(ll u, ll v, ll w, ll c) {
adj[u].push_back(v);
adj[v].push_back(u);
cost[u][v] += w;
cost[v][u] -= w;
cap[u][v] = c;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.setf(ios::fixed);
cout.precision(6);
ll tc;
cin>>tc;
while(tc--) {
ll n, m;
cin>>n>>m;
memset(cost, 0, sizeof(cost));
memset(flo, 0, sizeof(flo));
memset(cap, 0, sizeof(cap));
for(ll i = 0; i < MAX_N; i++) adj[i].clear();
connect(source, bridge, 0, 2);
ll gap = 300;
for(ll i = 1; i <= n; i++) {
connect(bridge, i, 0, 1);
connect(i, i + gap, -1, 1);
connect(i + gap, sink, 0, 1);
}
while(m--) {
ll u, v;
cin>>u>>v;
connect(u + gap,v,0,1);
}
cout<<solve()<<'\n';
}
return 0;
}
|
