[BOJ] 11493 동전 교환

동전 교환

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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")//Comment optimisations for interactive problems (use endl)
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimization ("unroll-loops")

#define MAX_N 1010
#define INF 987654321
#define ll long long
#define pll pair<ll, ll>
#define vpll vector<pll>
#define vall3 vector<array<ll,3>>
#define all5 array<ll,5>
#define vall5 vector<all5>
#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 = 1004, sink = 1005;
ll cap[MAX_N][MAX_N], cost[MAX_N][MAX_N], flo[MAX_N][MAX_N], path[MAX_N], dis[MAX_N][MAX_N];
vll adj[MAX_N], edges[MAX_N];

void floyd(ll n) {
for(ll i = 1; i <= n; i++) dis[i][i] = 0;

for(ll k = 1; k <= n; k++) {
for(ll i = 1; i <= n; i++) {
for(ll j = 1; j <= n; j++) {
dis[i][j] = min(dis[i][j], dis[i][k] + dis[k][j]);
}
}
}
}

void connect(ll u, ll v, ll capacity, ll weight) {
adj[u].push_back(v);
adj[v].push_back(u);

cap[u][v] = capacity;

cost[u][v] = weight;
cost[v][u] = -weight;
}

bool bfs(ll u, ll v) {
vll w(MAX_N, INF);
bool inc[MAX_N];
memset(path, 0, sizeof path);
memset(inc, 0, sizeof inc);
queue<ll> q;
q.push(u);
w[u] = 0;

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 = INF, sum = 0;
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];
sum += mi * cost[u][v];
flo[u][v] += mi;
flo[v][u] -= mi;
v = u;
}
res += max(sum, 0ll);

}
return res;
}

int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.setf(ios::fixed);
cout.precision(6);
ll tc, n, m;

cin>>tc;
while(tc--) {
cin>>n>>m;

for(ll i = 0; i < MAX_N; i++) {
adj[i].clear();
edges[i].clear();
}

memset(flo, 0, sizeof flo);
memset(cap, 0, sizeof cap);
memset(cost, 0, sizeof cost);
memset(dis, 0x0f, sizeof dis);

for(ll i = 0, u, v; i < m; i++) {
cin>>u>>v;
edges[u].push_back(v);
edges[v].push_back(u);
dis[u][v] = dis[v][u] = 1;
}

floyd(n);

for(ll i = 1, c; i <= n; i++) {
cin>>c;
if(c) {
connect(source, i, 1, 0);
}
}
for(ll i = 1, c, gap = 500; i <= n; i++) {
cin>>c;
if(c) {
for(auto& v : adj[source]) {
connect(v, i + gap, INF, dis[v][i]);
}

connect(i + gap, sink, 1, 0);
}
}


cout<<solve()<<'\n';
}

return 0;
}
Author: Song Hayoung
Link: https://songhayoung.github.io/2022/04/29/PS/BOJ/11493/
Copyright Notice: All articles in this blog are licensed under CC BY-NC-SA 4.0 unless stating additionally.