P5192 Zoj3229 Shoot the Bullet|东方文花帖|【模板】有源汇上下界最大流

https://www.luogu.com.cn/record/103045513

Luogu/P5192/P5192.cpp

@@ -0,0 +1,162 @@
+#include <iostream>
+#include <algorithm>
+#include <iterator>
+#include <queue>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 2e5 + 5,
+          M = 2e6 + 5;
+const int INF = 0x3f3f3f3f;
+
+int n, m, s, t, ss, tt;
+int idx, head[N], ver[M << 2], edge[M << 2], next[M << 2];
+int f[N], d[N], cur[N];
+
+void add(int u, int v, int w) {
+    ver[idx] = v;
+    edge[idx] = w;
+    next[idx] = head[u];
+    head[u] = idx++;
+}
+
+bool bfs() {
+    std::fill(std::begin(d), std::end(d), 0);
+
+    std::queue<int> q;
+    q.push(s);
+    d[s] = 1;
+    cur[s] = head[s];
+
+    while (!q.empty()) {
+        int u = q.front();
+        q.pop();
+
+        for (int i = head[u]; ~i; i = next[i]) {
+            int v = ver[i],
+                w = edge[i];
+
+            if (!d[v] && w) {
+                d[v] = d[u] + 1;
+                cur[v] = head[v];
+
+                if (v == t) return true;
+
+                q.push(v);
+            }
+        }
+    }
+
+    return false;
+}
+
+int dinic(int u, int limit) {
+    if (u == t) return limit;
+
+    int flow = 0;
+
+    for (int i = cur[u]; ~i && flow < limit; i = next[i]) {
+        cur[u] = i;
+
+        int v = ver[i],
+            w = edge[i];
+
+        if (d[v] == d[u] + 1 && w) {
+            int k = dinic(v, std::min(w, limit - flow));
+
+            if (!k) d[v] = 0;
+
+            edge[i] -= k;
+            edge[i ^ 1] += k;
+            flow += k;
+        }
+    }
+
+    return flow;
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    while (cin >> n >> m) {
+        idx = 0;
+        std::fill(std::begin(head), std::end(head), -1);
+        std::fill(std::begin(f), std::end(f), 0);
+
+        ss = 0, tt = n + m + 1;
+
+        for (int i = 1, x; i <= m; i++) {
+            cin >> x;
+
+            add(ss, i, INF - x);
+            add(i, ss, 0);
+
+            f[ss] -= x;
+            f[i] += x;
+        }
+
+        for (int i = 1, c, d; i <= n; i++) {
+            cin >> c >> d;
+
+            add(m + i, tt, d);
+            add(tt, m + i, 0);
+
+            for (int j = 1, t, l, r; j <= c; j++) {
+                cin >> t >> l >> r;
+
+                t++;
+
+                add(t, m + i, r - l);
+                add(m + i, t, 0);
+
+                f[t] -= l;
+                f[m + i] += l;
+            }
+        }
+
+        int sum = 0;
+        s = n + m + 2, t = n + m + 3;
+
+        for (int i = 0; i <= n + m + 1; i++) {
+            if (f[i] > 0) {
+                add(s, i, f[i]);
+                add(i, s, 0);
+                sum += f[i];
+            } else if (f[i] < 0) {
+                add(i, t, -f[i]);
+                add(t, i, 0);
+            }
+        }
+
+        add(tt, ss, INF);
+        add(ss, tt, 0);
+
+        int res = 0;
+        while (bfs()) {
+            while (int flow = dinic(s, INF)) res += flow;
+        }
+
+        if (res == sum) {
+            int x = edge[idx - 1];
+            edge[idx - 1] = edge[idx - 2] = 0;
+
+            s = ss, t = tt;
+
+            int res = 0;
+            while (bfs()) {
+                while (int flow = dinic(s, INF)) res += flow;
+            }
+
+            cout << x + res << endl;
+        } else {
+            cout << -1 << endl;
+        }
+
+        cout << endl;
+    }
+
+    return 0;
+}