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| #include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10;
const int M = 5e5 + 10;
const int inf = 0x7fffffff;
struct edge {
int u, v, c, val, nxt;
edge(int u = 0, int v = 0, int c = 0, int val = 0, int nxt = 0) : u(u), v(v), c(c), val(val), nxt(nxt) {}
} e[M];
int head[N];
int cnt = 1;
int now[N];
void ADD(int u, int v, int c, int val) {
cnt++;
e[cnt] = edge(u, v, c, val, head[u]);
head[u] = cnt;
}
void add_edge(int u, int v, int c, int val) {
ADD(u, v, c, val);
ADD(v, u, 0, -val);
}
int n, m, T;
int s, t;
struct Node {
int name, dis;
bool operator<(const Node &a) const {
return dis > a.dis;
}
};
int dis[N];
bool vis[N];
int h[N];
int pro[N];
int flow[N];
int mn, mx;
bool dj() {
for (int i = 1; i <= n; i++) flow[i] = dis[i] = inf;
for (int i = 1; i <= n; i++) pro[i] = -1;
memcpy(now, head, sizeof head);
dis[1] = 0;
priority_queue<Node>q;
q.push({1, dis[1]});
while (q.size()) {
int u = q.top().name;
int d = q.top().dis;
q.pop();
if (d > dis[u]) continue;
for (int i = head[u]; i; i = e[i].nxt) {
int v = e[i].v;
int c = e[i].c;
if (!c) continue;
int val = e[i].val;
if (dis[v] > max(dis[u], val)) {
dis[v] = max(dis[u], val);
flow[v] = min(flow[u], c);
pro[v] = i;
q.push({v, dis[v]});
}
}
}
return dis[t] == inf;
}
void maxflow() {
while (!dj()) {
mx += flow[t];
mn = max(mn, dis[t]);
if (mx >= T) {
cout << mn;
exit(0);
}
int u = t;
while (u != s) {
e[pro[u]].c -= flow[t];
e[pro[u] ^ 1].c += flow[t];
u = e[pro[u]].u;
}
}
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(0);
cin >> n >> m >> T;
s = 1, t = n;
for (int i = 1; i <= m; i++) {
int a, b, l;
cin >> a >> b >> l;
add_edge(a, b, 1, l);
add_edge(b, a, 1, l);
}
maxflow();
}
|