diff --git a/graph/bounded_flow.cc b/graph/bounded_flow.cc
new file mode 100644
index 0000000..82b2eff
--- /dev/null
+++ b/graph/bounded_flow.cc
@@ -0,0 +1,39 @@
+struct bounded_flow {
+    int n, m, S, T;
+    dinic net;
+    ll sum;
+    vector<ll> fl;
+    vector<ll> init;
+    bounded_flow(int n, int m) : sum(0), n(n), m(m), S(0), T(n + 1), net(n + 1), fl(m), init(n + 1) {}
+    void add_edge(int from, int to, ll low, ll high, int edge_id = -1) {
+        if (edge_id != -1) {
+            fl[edge_id] += low;
+        }
+        net.add_edge(from, to, high - low, edge_id, -1);
+        init[to] += low, init[from] -= low;
+    }
+    optional<pair<ll, vector<ll>>> run(int s, int t) {
+        for (int i = 1; i <= n; ++i) {
+            if (init[i] > 0) {
+                net.add_edge(S, i, init[i], -1, -1);
+                sum += init[i];
+            } else if (init[i] < 0) {
+                net.add_edge(i, T, -init[i], -1, -1);
+            }
+        }
+        net.add_edge(t, s, INFLL, -1, -1);
+        if (sum != net.run(S, T)) {
+            return nullopt;
+        } else {
+            auto res_flow = net.run(s, t);
+            for (int from = 1; from <= n; ++from) {
+                for (auto&& [to, cap, flow, rev, mark] : net.edges[from]) {
+                    if (mark != -1) {
+                        fl[mark] = flow;
+                    }
+                }
+            }
+            return {{res_flow, fl}};
+        }
+    }
+};