You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

60 lines
1.5 KiB
C++

#include <cstdio>
#include <cstring>
inline int min(int a, int b) { return a < b ? a : b; }
const int inf = 0x3f3f3f3f;
int adj[205], nxt[405], to[405], cap[405], cur[205], dis[405], ecnt;
inline void addEdge_impl_(int f, int t, int c)
{
nxt[ecnt] = adj[f];
adj[f] = ecnt;
to[ecnt] = t;
cap[ecnt] = c;
ecnt++;
}
inline void addEdge(int f, int t, int c)
{
addEdge_impl_(f, t, c);
addEdge_impl_(t, f, 0);
}
int n, m;
bool bfs()
{
static int que[205];
for (int i = 1; i <= n; i++)
cur[i] = adj[i], dis[i] = inf;
int len = dis[1] = 0;
que[len++] = 1;
for (int i = 0; i < len; i++)
for (int e = adj[que[i]]; ~e; e = nxt[e])
if (cap[e] && dis[to[e]] > dis[que[i]] + 1)
dis[que[len++] = to[e]] = dis[que[i]] + 1;
return dis[n] < inf;
}
int dinic(const int u, const int flow)
{
if (u == n)
return flow;
int res = 0;
for (int e = cur[u], curFlow; ~e; e = nxt[e])
if (cap[e] && dis[u] == dis[to[e]] - 1)
if (curFlow = dinic(to[e], min(cap[e], flow - res)))
res += curFlow, cap[e] -= curFlow, cap[e ^ 1] += curFlow, cur[u] = e;
if (res != flow)
dis[u] = inf;
return res;
}
int main()
{
while (~scanf("%d%d", &m, &n))
{
ecnt = 0;
memset(adj, -1, sizeof(adj));
for (int i = 0, x, y, z; i < m; i++)
scanf("%d%d%d", &x, &y, &z), addEdge(x, y, z);
int ans = 0;
while (bfs())
ans += dinic(1, inf);
printf("%d\n", ans);
}
return 0;
}