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| #include <iostream>
#include <queue>
#define maxn 20010
#define maxm 200010
#define INF 1000000000
using namespace std;
int n, m;
struct node {
int u, v, w;
} a[maxm];
struct Edge {
int to, next, w;
} e[1000010]; int c1, head[maxn];
inline void add_edge(int u, int v, int w) {
e[c1].to = v; e[c1].w = w;
e[c1].next = head[u]; head[u] = c1++;
}
inline void Add_edge(int u, int v, int w) {
add_edge(u, v, w); add_edge(v, u, 0);
}
int dep[maxn], s, t, w;
bool bfs() {
fill(dep, dep + maxn, 0); dep[s] = 1;
queue<int> Q; Q.push(s);
while (!Q.empty()) {
int u = Q.front(); Q.pop();
for (int i = head[u]; ~i; i = e[i].next) {
int v = e[i].to, w = e[i].w;
if (w > 0 && !dep[v]) {
dep[v] = dep[u] + 1;
if (v == t) return 1; Q.push(v);
}
}
}
return 0;
}
int dfs(int u, int _w) {
if (u == t || !_w) return _w;
int s = 0;
for (int i = head[u]; ~i; i = e[i].next) {
int v = e[i].to, w = e[i].w;
if (w > 0 && dep[v] == dep[u] + 1) {
int di = dfs(v, min(_w - s, w));
e[i].w -= di; e[i ^ 1].w += di;
s += di; if (s == _w) break;
}
}
if (s < _w) dep[u] = 0;
return s;
}
int dinic() {
int mf = 0;
while (bfs()) mf += dfs(s, INF);
return mf;
}
int main() { fill(head, head + maxn, -1);
ios::sync_with_stdio(false);
cin.tie(nullptr); cout.tie(nullptr);
cin >> n >> m;
for (int i = 1; i <= m; ++i) cin >> a[i].u >> a[i].v >> a[i].w;
cin >> s >> t >> w; int ans = 0;
for (int i = 1; i <= m; ++i) {
int u = a[i].u, v = a[i].v, w = a[i].w;
if (w < ::w) Add_edge(u, v, 1), Add_edge(v, u, 1);
} ans += dinic();
fill(head, head + maxn, -1); c1 = 0;
for (int i = 1; i <= m; ++i) {
int u = a[i].u, v = a[i].v, w = a[i].w;
if (w > ::w) Add_edge(u, v, 1), Add_edge(v, u, 1);
} ans += dinic();
cout << ans << "\n";
return 0;
}
|