1 files changed, 72 insertions, 0 deletions
diff --git a/content/string/suffixTree.cpp b/content/string/suffixTree.cpp
new file mode 100644
index 0000000..7112f39
--- /dev/null
+++ b/content/string/suffixTree.cpp
@@ -0,0 +1,72 @@
+struct SuffixTree {
+	struct Vert {
+		int start, end, suf; //s[start...end) along parent edge
+		map<char, int> nxt;
+	};
+	string s;
+	int needsSuffix, pos, remainder, curVert, curEdge, curLen;
+	// Each Vertex gives its children range as [start, end)
+	vector<Vert> tree = {Vert{-1, -1, 0, {}}};
+
+	SuffixTree(const string& s_) : s(s_) {
+		needsSuffix = remainder = curVert = curEdge = curLen = 0;
+		pos = -1;
+		for (int i = 0; i < sz(s); i++) extend();
+	}
+
+	int newVert(int start, int end) {
+		tree.push_back({start, end, 0, {}});
+		return sz(tree) - 1;
+	}
+
+	void addSuffixLink(int vert) {
+		if (needsSuffix) tree[needsSuffix].suf = vert;
+		needsSuffix = vert;
+	}
+
+	bool fullImplicitEdge(int vert) {
+		int len = min(tree[vert].end, pos + 1) - tree[vert].start;
+		if (curLen >= len) {
+			curEdge += len;
+			curLen -= len;
+			curVert = vert;
+			return true;
+		} else {
+			return false;
+	}}
+
+	void extend() {
+		pos++;
+		needsSuffix = 0;
+		remainder++;
+		while (remainder) {
+			if (curLen == 0) curEdge = pos;
+			if (!tree[curVert].nxt.count(s[curEdge])) {
+				int leaf = newVert(pos, sz(s));
+				tree[curVert].nxt[s[curEdge]] = leaf;
+				addSuffixLink(curVert);
+			} else {
+				int nxt = tree[curVert].nxt[s[curEdge]];
+				if (fullImplicitEdge(nxt)) continue;
+				if (s[tree[nxt].start + curLen] == s[pos]) {
+					curLen++;
+					addSuffixLink(curVert);
+					break;
+				}
+				int split = newVert(tree[nxt].start,
+				                    tree[nxt].start + curLen);
+				tree[curVert].nxt[s[curEdge]] = split;
+				int leaf = newVert(pos, sz(s));
+				tree[split].nxt[s[pos]] = leaf;
+				tree[nxt].start += curLen;
+				tree[split].nxt[s[tree[nxt].start]] = nxt;
+				addSuffixLink(split);
+			}
+			remainder--;
+			if (curVert == 0 && curLen) {
+				curLen--;
+				curEdge = pos - remainder + 1;
+			} else {
+				curVert = tree[curVert].suf ? tree[curVert].suf : 0;
+	}}}
+};
+\ No newline at end of file