more stuff

3 files changed, 59 insertions, 6 deletions

diff --git a/content/geometry/segmentIntersection.cpp b/content/geometry/segmentIntersection.cpp
index acce7cc..afc01b2 100644
--- a/content/geometry/segmentIntersection.cpp
+++ b/content/geometry/segmentIntersection.cpp
@@ -29,7 +29,7 @@ bool lessPT(const pt& a, const pt& b) {
 }
 
 bool intersect(const seg& a, const seg& b) {
-	return lineSegmentIntersection(a.a, a.b, b.a, b.b);
+	return segmentIntersection(a.a, a.b, b.a, b.b); //@\sourceref{geometry/linesAndSegments.cpp}@
 }
 
 pair<int, int> intersect(vector<seg>& segs) {
diff --git a/content/graph/dinic.cpp b/content/graph/dinic.cpp
new file mode 100644
index 0000000..2e58a2d
--- /dev/null
+++ b/content/graph/dinic.cpp
@@ -0,0 +1,55 @@
+struct Edge {
+	int to, rev;
+	ll f, c;
+};
+
+vector<vector<Edge>> adj;
+int s, t;
+vector<int> pt, dist;
+
+void addEdge(int u, int v, ll c) {
+	adj[u].push_back({v, (int)sz(adj[v]), 0, c});
+	adj[v].push_back({u, (int)sz(adj[u]) - 1, 0, 0});
+}
+
+bool bfs() {
+	dist.assign(sz(adj), -1);
+	dist[s] = 0;
+	queue<int> q({s});
+	while (!q.empty() && dist[t] < 0) {
+		int v = q.front(); q.pop();
+		for (Edge& e : adj[v]) {
+			if (dist[e.to] < 0 && e.c - e.f > 0) {
+				dist[e.to] = dist[v] + 1;
+				q.push(e.to);
+	}}}
+	return dist[t] >= 0;
+}
+
+ll dfs(int v, ll flow = INF) {
+	if (v == t || flow == 0) return flow;
+	for (; pt[v] < sz(adj[v]); pt[v]++) {
+		Edge& e = adj[v][pt[v]];
+		if (dist[e.to] != dist[v] + 1) continue;
+		ll cur = dfs(e.to, min(e.c - e.f, flow));
+		if (cur > 0) {
+			e.f += cur;
+			adj[e.to][e.rev].f -= cur;
+			return cur;
+	}}
+	return 0;
+}
+
+ll maxFlow(int source, int target) {
+	s = source, t = target;
+	ll flow = 0;
+	while (bfs()) {
+		pt.assign(sz(adj), 0);
+		ll cur;
+		do {
+			cur = dfs(s);
+			flow += cur;
+		} while (cur > 0);
+	}
+	return flow;
+}
diff --git a/content/string/duval.cpp b/content/string/duval.cpp
index bf36cce..253bae1 100644
--- a/content/string/duval.cpp
+++ b/content/string/duval.cpp
@@ -6,9 +6,8 @@ vector<pair<int, int>> duval(const string& s) {
 			if (s[k] < s[j]) k = i;
 			else k++;
 		}
-		while (i <= k) {
+		for (; i <= k; i += j - k) {
 			res.push_back({i, i + j - k});
-			i += j - k;
 	}}
 	return res;
 }
@@ -16,6 +15,5 @@ vector<pair<int, int>> duval(const string& s) {
 int minrotation(const string& s) {
 	auto parts = duval(s+s);
 	for (auto [l, r] : parts) {
-		if (l < sz(s) && r >= sz(s)) {
-			return l;
-}}}
+		if (r >= sz(s)) return l;
+}}